Mizuho Financial (MFG) 20-F 1 Jul 22 2022 FY Annual report (foreign) Financial data

Cover Page

Cover Page	12 Months Ended
	Mar. 31, 2022 shares
Document Information [Line Items]
Document Type	20-F
Amendment Flag	false
Document Period End Date	Mar. 31, 2022
Document Fiscal Year Focus	2022
Document Fiscal Period Focus	FY
Entity Registrant Name	Mizuho Financial Group, Inc.
Entity Central Index Key	0001335730
Current Fiscal Year End Date	--03-31
Entity Well-known Seasoned Issuer	Yes
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Entity Interactive Data Current	Yes
Document Annual Report	true
Document Transition Report	false
Document Shell Company Report	false
Entity Shell Company	false
Entity Filer Category	Large Accelerated Filer
Entity Emerging Growth Company	false
Entity Common Stock, Shares Outstanding	2,539,249,894
Document Accounting Standard	U.S. GAAP
Entity File Number	001-33098
Entity Incorporation, State or Country Code	M0
Document Registration Statement	false
Entity Address, Address Line One	1-5-5 Otemachi
Entity Address, City or Town	Chiyoda-ku
Entity Address, Postal Zip Code	100-8176
Entity Address, Country	JP
ICFR Auditor Attestation Flag	true
Auditor Name	Ernst & Young ShinNihon LLC
Auditor Firm ID	789
Auditor Location	Tokyo, Japan
Business Contact [Member]
Document Information [Line Items]
Contact Personnel Name	Yasutoshi Tanaka
Entity Address, Address Line One	1-5-5 Otemachi
Entity Address, City or Town	Chiyoda-ku
Entity Address, Postal Zip Code	100-8176
Entity Address, Country	JP
City Area Code	81-3
Local Phone Number	5224-1111
American depositary shares
Document Information [Line Items]
Security Exchange Name	NYSE
Title of 12(b) Security	American depositary shares, each of which represents two shares of common stock
Trading Symbol	MFG
Common Stock
Document Information [Line Items]
Title of 12(b) Security	Common Stock, without par value
No Trading Symbol Flag	true

CONSOLIDATED BALANCE SHEETS

CONSOLIDATED BALANCE SHEETS - JPY (¥) ¥ in Millions	Mar. 31, 2022	Mar. 31, 2021
Assets:
Cash and due from banks	¥ 2,290,377	¥ 1,600,555
Interest-bearing deposits in other banks	49,883,912	47,133,541
Call loans and funds sold	1,102,296	858,806
Receivables under resale agreements	12,751,085	11,623,438
Receivables under securities borrowing transactions	2,338,796	2,694,107
Trading account assets	24,652,067	26,753,109
Investments (Note 3):
Available-for-sale securities (including assets pledged that secured parties are permitted to sell or repledge of ¥1,416,772 million in 2021 and ¥1,120,839 million in 2022), net of allowance	31,673,890	27,853,035
Held-to-maturity securities (including assets pledged that secured parties are permitted to sell or repledge of ¥97,949 million in 2021 and ¥1,019,391 million in 2022)	1,519,055	887,149
Equity securities	3,572,908	3,785,916
Other investments	582,388	515,346
Loans (Notes 4 and 5)	90,290,583	88,580,867
Allowance for credit losses on loans	(809,817)	(650,849)
Loans, net of allowance	89,480,766	87,930,018
Premises and equipment—net (Note 6)	1,704,067	1,811,458
Due from customers on acceptances	271,877	237,348
Accrued income	322,025	316,834
Goodwill (Note 7)	92,695	92,695
Intangible assets (Note 7)	47,939	56,121
Deferred tax assets	277,319	44,970
Other assets (Note 12)	8,987,242	7,457,028
Total assets	231,550,704	221,651,474
Liabilities and equity:
Noninterest-bearing deposits	32,844,872	29,818,303
Interest-bearing deposits	91,425,213	92,037,375
Noninterest-bearing deposits	2,500,823	2,332,218
Interest-bearing deposits	30,407,376	26,822,708
Due to trust accounts	390,247	380,793
Call money and funds purchased	1,278,051	1,312,790
Payables under repurchase agreements (Note 29)	20,069,566	18,607,147
Payables under securities lending transactions (Note 29)	1,360,743	1,208,031
Other short-term borrowings (Note 11)	7,566,771	9,085,912
Trading account liabilities	14,859,383	10,877,538
Bank acceptances outstanding	271,877	237,348
Income taxes payable	62,697	56,665
Deferred tax liabilities	29,033	76,957
Accrued expenses	203,383	194,303
Long-term debt	12,578,216	11,706,471
Other liabilities (Note 12)	6,260,222	7,208,758
Total	222,108,473	211,963,317
Commitments and contingencies (Note 23)
MHFG shareholders' equity:
Common stock (Note 14)—no par value, authorized 4,800,000,000 shares in 2021 and 2022, and issued 0 shares in 2021 and 2022	5,816,834	5,826,863
Retained earnings	2,665,608	2,967,385
Accumulated other comprehensive income (loss), net of tax (Note 16)	440,112	318,114
Less: Treasury stock, at cost—Common stock 3,889,782 shares in 2021, and 0 shares in 2022	(8,342)	(7,124)
Total MHFG shareholders' equity	8,914,212	9,105,238
Noncontrolling interests	528,019	582,919
Total equity	9,442,231	9,688,157
Total liabilities and equity	231,550,704	221,651,474
Consolidated VIEs
Assets:
Cash and due from banks	2,243	315
Interest-bearing deposits in other banks	71,573	46,143
Call loans and funds sold	162,578	269,030
Trading account assets	2,222,902	2,539,589
Investments (Note 3):
Investments	238,624	100,928
Loans, net of allowance	8,347,880	8,277,276
Other assets (Note 12)	529,178	540,124
Total assets	11,574,978	11,773,405
Liabilities and equity:
Payables under securities lending transactions (Note 29)	51,752	73,630
Other short-term borrowings (Note 11)	53,668	36,546
Trading account liabilities	51,019	58,935
Long-term debt	1,024,067	593,719
Other liabilities (Note 12)	1,041,938	954,599
Total	¥ 2,222,444	¥ 1,717,429

CONSOLIDATED BALANCE SHEETS (Pa

CONSOLIDATED BALANCE SHEETS (Parenthetical) - JPY (¥) ¥ in Millions	Mar. 31, 2022	Mar. 31, 2021
Trading account assets, assets pledged that secured parties are permitted to sell or repledge	¥ 4,639,282	¥ 6,249,224
Available-for-sale securities, assets pledged that secured parties are permitted to sell or repledge	1,120,839	1,416,772
Held-to-maturity securities, assets pledged that secured parties are permitted to sell or repledge	1,019,391	97,949
Long-term debt, liabilities accounted for at fair value	¥ 2,756,062	¥ 2,703,021
Common stock, par value	¥ 0	¥ 0
Common stock, authorized	4,800,000,000	4,800,000,000
Common stock, issued	2,539,249,894	2,539,249,894
Treasury stock, shares	4,659,024	3,889,782

CONSOLIDATED STATEMENTS OF INCO

CONSOLIDATED STATEMENTS OF INCOME - JPY (¥) ¥ in Millions		12 Months Ended
		Mar. 31, 2022	Mar. 31, 2021	Mar. 31, 2020
Interest and dividend income:
Loans, including fees		¥ 957,579	¥ 1,018,766	¥ 1,380,828
Investments:
Interest		63,050	55,482	89,749
Dividends		83,589	56,847	76,150
Trading account assets		245,146	236,620	221,983
Call loans and funds sold		1,377	2,186	5,434
Receivables under resale agreements and securities borrowing transactions		36,479	42,350	271,598
Deposits in other banks		56,721	44,305	105,430
Total interest and dividend income		1,443,941	1,456,556	2,151,172
Interest expense:
Deposits		76,292	160,315	615,785
Trading account liabilities		59,739	52,682	52,955
Call money and funds purchased		1,093	1,829	8,830
Payables under repurchase agreements and securities lending transactions		40,672	54,655	358,862
Other short-term borrowings		5,623	18,432	29,813
Long-term debt		190,713	180,026	205,136
Total interest expense		374,132	467,939	1,271,381
Net interest income		1,069,809	988,617	879,791
Provision (credit) for credit losses (Note 3 and 5)		214,408	112,776	156,200
Net interest income after provision (credit) for credit losses		855,401	875,841	723,591
Noninterest income (Note 25):
Fee and commission income		980,000	912,684	867,885
Foreign exchange gains (losses)—net (Note 26)	[1]	91,611	89,267	44,345
Trading account gains (losses)—net (Note 26)		(491,947)	120,596	745,692
Investment gains (losses)—net
Debt securities		(14,777)	(22,032)	31,032
Equity securities		(60,563)	850,567	(557,391)
Equity in earnings (losses) of equity method investees—net	[2]	34,587	31,027	34,012
Gains on disposal of premises and equipment		9,943	7,125	2,583
Other noninterest income	[3],[4]	120,936	52,086	139,582
Total noninterest income		669,790	2,041,320	1,307,740
Noninterest expenses:
Salaries and employee benefits		669,474	685,692	677,332
General and administrative expenses		611,326	623,732	649,498
Occupancy expenses		201,987	206,470	214,851
Fee and commission expenses		203,957	190,489	194,010
Provision (credit) for credit losses on off-balance-sheet instruments		(14,819)	18,007	19,262
Other noninterest expenses		95,754	164,007	122,888
Total noninterest expenses		1,767,679	1,888,397	1,877,841
Income (loss) before income tax expense (benefit)		(242,488)	1,028,764	153,490
Income tax expense (Note 19)		(141,017)	210,716	47,175
Net income (loss)		(101,471)	818,048	106,315
Less: Net income (loss) attributable to noncontrolling interests		3,251	236,283	(43,880)
Net income (loss) attributable to MHFG shareholders		¥ (104,722)	¥ 581,765	¥ 150,195
Earnings per common share (Note 18):
Basic net income (loss) per common share		¥ (41.28)	¥ 229.27	¥ 59.19
Diluted net income (loss) per common share	[5]	(41.28)	229.26	59.19
Dividends Per Share [Abstract]
Common stock		¥ 80	¥ 75	¥ 75
[1]Amounts include realized and unrealized gains and losses on both derivative instruments and nonderivative instruments. Amounts on derivative instruments include gains and losses on forward foreign exchange contracts and currency options. Amounts on nonderivative instruments include translation gains and losses related to foreign currency-denominated debt securities reported as Trading securities.[2]These amounts are revenues from contracts that do not meet the scope of ASC 606.[3]Part of these amounts are considered to be revenues from contracts that are within the scope of ASC 606.[4]These amounts include the net unrealized gains resulting from changes in fair values of structured notes that contain embedded derivatives. See Note 27 “Fair value” for further details.[5]For the fiscal years ended March 31, 2020, 2021 and 2022, the performance-based plan under the stock compensation programs could potentially dilute earnings per common share but were not included in the computation of diluted earnings per common share due to their antidilutive effects. In addition, for the fiscal year ended March 31, 2022, the computation of diluted earnings per common share did not assume exercise of stock options, as the effect of such exercise would be anti-dilutive due to net loss.

CONSOLIDATED STATEMENTS OF COMP

CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - JPY (¥) ¥ in Millions	12 Months Ended
	Mar. 31, 2022	Mar. 31, 2021	Mar. 31, 2020
Net income	¥ (101,471)	¥ 818,048	¥ 106,315
Other comprehensive income (loss), net of tax:
Net unrealized gains (losses) on available-for-sale securities, net of tax	(17,020)	11,534	(41,483)
Foreign currency translation adjustments, net of tax	185,298	22,695	(50,576)
Defined benefit plan adjustments, net of tax	(41,385)	328,066	(126,915)
Own credit risk adjustments, net of tax	(300)	(35,187)	46,919
Total other comprehensive income (loss), net of tax	126,593	327,108	(172,055)
Total comprehensive income (loss)	25,122	1,145,156	(65,740)
Less: Total comprehensive income (loss) attributable to noncontrolling interests	7,846	235,784	(43,472)
Total comprehensive income (loss) attributable to MHFG shareholders	¥ 17,276	¥ 909,372	¥ (22,268)

CONSOLIDATED STATEMENTS OF EQUI

CONSOLIDATED STATEMENTS OF EQUITY - JPY (¥) ¥ in Millions	Total	Common Stock	Retained Earnings	Retained Earnings Cumulative effect, period of adoption, adjusted balance		Accumulated other comprehensive income (loss)	[2]	Accumulated other comprehensive income (loss) Cumulative effect, period of adoption, adjusted balance		Treasury Stock	Parent	Noncontrolling Interest
Balance at beginning of fiscal year at Mar. 31, 2019		¥ 5,829,657	¥ 2,740,545	¥ 1,052	[1]	¥ 164,021		¥ (1,052)	[1],[2]	¥ (7,704)		¥ 774,974
Purchases of treasury stock										(1,908)
Balance at beginning of fiscal year, adjusted at Mar. 31, 2019				2,741,597				162,969	[2]
Performance-based stock compensation program		(178)
Change in ownership interests in consolidated subsidiaries		(1,965)
Disposal of treasury stock										3,197
Net income (loss) attributable to MHFG shareholders	¥ 150,195		150,195
Change during year	(172,055)					(172,463)
Other		(14)	(612)
Transactions between the MHFG Group and the noncontrolling interest shareholders												(52,521)
Dividends paid to noncontrolling interests												(15,722)
Dividends declared			(190,406)
Net income (loss) attributable to noncontrolling interests	(43,880)											(43,880)
Other												408
Balance at end of fiscal year at Mar. 31, 2020	9,175,624	5,827,500	2,700,774	(124,636)	[3]	(9,494)		0		(6,415)	¥ 8,512,365	663,259
Purchases of treasury stock										(2,545)
Balance at beginning of fiscal year, adjusted at Mar. 31, 2020				2,576,138				(9,494)	[2]
Performance-based stock compensation program		(110)
Change in ownership interests in consolidated subsidiaries		(527)
Disposal of treasury stock										1,836
Net income (loss) attributable to MHFG shareholders	581,765		581,765
Change during year	327,108					327,608
Other		0	(100)
Transactions between the MHFG Group and the noncontrolling interest shareholders												(300,371)
Dividends paid to noncontrolling interests												(15,753)
Dividends declared			(190,418)
Net income (loss) attributable to noncontrolling interests	236,283											236,283
Other												(499)
Balance at end of fiscal year at Mar. 31, 2021	9,688,157	5,826,863	2,967,385	0		318,114		0	[2]	(7,124)	9,105,238	582,919
Purchases of treasury stock										(2,870)
Balance at beginning of fiscal year, adjusted at Mar. 31, 2021				¥ 2,967,385				¥ 318,114	[2]
Performance-based stock compensation program		(69)
Change in ownership interests in consolidated subsidiaries		(9,960)
Disposal of treasury stock										1,652
Net income (loss) attributable to MHFG shareholders	(104,722)		(104,722)
Change during year	126,593					121,998
Other		0	(309)
Transactions between the MHFG Group and the noncontrolling interest shareholders												(44,651)
Dividends paid to noncontrolling interests												(18,095)
Dividends declared			(196,746)
Net income (loss) attributable to noncontrolling interests	3,251											3,251
Other												4,595
Balance at end of fiscal year at Mar. 31, 2022	¥ 9,442,231	¥ 5,816,834	¥ 2,665,608			¥ 440,112				¥ (8,342)	¥ 8,914,212	¥ 528,019
[1]These amounts resulted from the adoption of ASU No.2017-12, “Derivatives and Hedging (Topic 815)—Targeted Improvements to Accounting for Hedging Activities.”[2]The amounts that have been reclassified out of Accumulated other comprehensive income (loss), net of tax into net income are presented in Note 16 “Accumulated other comprehensive income (loss), net of tax.”[3]These amounts resulted from the adoption of ASU No.2016-13, “Financial Instruments—Credit Losses (Topic 326)—Measurement of Credit Losses on Financial Instruments” and subsequent amendments. See Note 1 “Basis of presentation and summary of significant accounting policies” for further details.

CONSOLIDATED STATEMENTS OF CASH

CONSOLIDATED STATEMENTS OF CASH FLOWS - JPY (¥) ¥ in Millions		12 Months Ended
		Mar. 31, 2022	Mar. 31, 2021	Mar. 31, 2020
Cash flows from operating activities:
Net income (loss)		¥ (101,471)	¥ 818,048	¥ 106,315
Less: Net income (loss) attributable to noncontrolling interests		3,251	236,283	(43,880)
Net income (loss) attributable to MHFG shareholders		(104,722)	581,765	150,195
Adjustments to reconcile net income to net cash provided by (used in) operating activities:
Depreciation and amortization		228,397	231,677	243,724
Provision (credit) for credit losses		214,408	112,776	156,200
Investment losses (gains)—net		75,340	(828,535)	526,359
Equity in losses (earnings) of equity method investees—net	[1]	(34,587)	(31,027)	(34,012)
Foreign exchange losses (gains)—net		517,989	207,400	(139,900)
Deferred income tax expense (benefit)		(255,365)	50,701	(101,941)
Net change in trading account assets		2,386,304	1,567,897	(7,460,802)
Net change in trading account liabilities		3,634,056	(1,984,509)	2,599,090
Net change in loans held for sale		(126,804)	30,250	(60,189)
Net change in accrued income		4,680	8,052	14,060
Net change in accrued expenses		2,783	(72,850)	(24,345)
Other—net		(1,044,392)	595,159	90,489
Net cash provided by (used in) operating activities		5,498,087	468,756	(4,041,072)
Cash flows from investing activities:
Proceeds from sales of Available-for-sale securities		36,330,397	28,041,466	21,153,866
Proceeds from sales of Equity securities (Note)	[2]	2,526,075	3,089,202	3,123,341
Proceeds from maturities of Available-for-sale securities		39,008,678	31,521,663	15,350,105
Proceeds from maturities of Held-to-maturity securities		178,955	116,060	731,686
Purchases of Held-to-maturity securities		(714,794)	(134,660)
Purchases of Available-for-sale securities		(80,478,884)	(69,491,642)	(37,445,206)
Purchases of Equity securities (Note)	[2]	(2,208,196)	(2,979,434)	(2,900,020)
Proceeds from sales of loans		2,046,573	1,847,102	1,729,513
Net change in loans		(1,397,302)	(1,502,445)	(7,512,885)
Net change in call loans and funds sold, and receivables under resale agreements and securities borrowing transactions		(147,806)	6,906,483	(5,812,860)
Proceeds from sales of premises and equipment		18,720	13,664	16,825
Purchases of premises and equipment		(136,238)	(211,495)	(243,022)
Proceeds from sales of investments in subsidiaries (affecting the scope of consolidation)		50,699	218,259	1,068
Purchases of investments in subsidiaries (affecting the scope of consolidation)		(93,005)	(47,515)
Net cash provided by (used in) investing activities		(5,016,128)	(2,613,292)	(11,807,589)
Cash flows from financing activities:
Net change in deposits		3,589,567	4,394,481	7,920,701
Net change in call money and funds purchased, and payables under repurchase agreements and securities lending transactions		9,268	(962,754)	2,754,646
Net change in due to trust accounts		9,454	131,056	(62,610)
Net change in other short-term borrowings		(1,711,421)	4,085,165	2,936,677
Proceeds from issuance of long-term debt		3,004,293	2,568,730	2,303,803
Repayment of long-term debt		(2,715,054)	(1,511,050)	(3,273,353)
Proceeds from noncontrolling interests		101,755	236,868	131,795
Payments to noncontrolling interests		(80,493)	(37,928)	(148,673)
Proceeds from sales of treasury stock		874	854	1,517
Purchases of treasury stock		(1,927)	(1,849)	(1,441)
Purchases of treasury stock of subsidiaries		0	(5,414)
Dividends paid		(196,783)	(190,498)	(190,386)
Dividends paid to noncontrolling interests		(18,095)	(15,753)	(15,722)
Net cash provided by (used in) financing activities		1,991,438	8,691,908	12,356,954
Effect of exchange rate changes on cash and cash equivalents		966,796	235,610	(229,918)
Net increase (decrease) in cash and cash equivalents		3,440,193	6,782,982	(3,721,625)
Cash and cash equivalents at beginning of fiscal year		48,734,096	41,951,114	45,672,739
Cash and cash equivalents at end of fiscal year		52,174,289	48,734,096	41,951,114
Supplemental disclosure of cash flow information:
Interest paid		274,530	497,422	1,321,358
Income taxes paid		164,408	216,996	97,630
Noncash investing activities:
Transfer of loans into loans held-for-sale		¥ 15,916	¥ 20,335	¥ 29,953
[1]These amounts are revenues from contracts that do not meet the scope of ASC 606.[2]Proceeds from sales of Equity securities as well as Purchases of Equity securities include cash activity related to Other investments, the amounts of which are not significant.

Basis of presentation and summa

Basis of presentation and summary of significant accounting policies	12 Months Ended
	Mar. 31, 2022
Basis of presentation and summary of significant accounting policies	1. Basis of presentation and summary of significant accounting policies Basis of presentation Mizuho Financial Group, Inc. (“MHFG”) is a joint stock corporation with limited liability under the laws of Japan. MHFG is a holding company for Mizuho Bank, Ltd. (“MHBK”), Mizuho Trust & Banking Co., Ltd. (“MHTB”), Mizuho Securities Co., Ltd. (“MHSC”), Asset Management One Co., Ltd. (“Asset Management One”), and other subsidiaries. MHFG, through its subsidiaries (“the MHFG Group,” or “the Group”), provides domestic and international financial services in Japan and other countries. For a discussion of the Group’s segment information, see Note 31 “Business segment information.” MHFG and its domestic subsidiaries as well as its foreign subsidiaries maintain their accounting records in accordance with the accounting standards of Japan and those standards of the countries in which they are domiciled. Certain adjustments and reclassifications have been incorporated in the accompanying consolidated financial statements to conform them to the accounting principles generally accepted in the United States of America (“U.S. GAAP”). The consolidated financial statements are stated in Japanese yen, the currency of the country in which MHFG is incorporated and principally operates. The accompanying consolidated financial statements include the accounts of MHFG and its subsidiaries. MHFG’s fiscal year ends on March 31. MHFG’s subsidiaries fiscal year end is determined by each subsidiary. If the fiscal year end of a subsidiary has more than three months discrepancy from the MHFG’s fiscal year end, the subsidiary executes provisional financial closing. For those subsidiaries where the fiscal year end is not on March 31 and where the subsidiaries do not execute provisional financial close, the effect on the MHFG Group’s consolidated financial statements of all material events through the date of each of the periods presented in the consolidated financial statements has been considered for adjustment and/or disclosure. When determining whether to consolidate investee entities, the MHFG Group performs an analysis of the facts and circumstances of the particular relationships between the MHFG Group and the investee entities as well as the ownership of voting shares. The consolidated financial statements also include the accounts of VIEs for which MHFG or its subsidiaries have been determined to be the primary beneficiary in accordance with the Financial Accounting Standards Board (“FASB”) Accounting Standards Codification (“ASC”) 810, “Consolidation” (“ASC 810”). All significant intercompany transactions and balances have been eliminated upon consolidation. The MHFG Group accounts for investments in entities over which it has significant influence by using the equity method of accounting. These investments are included in Other investments and the Group’s proportionate share of income or loss is included in Equity in earnings (losses) of equity method investees—net. Certain comparative amounts for the prior period have been reclassified in order to conform to the current period’s presentation. Use of estimates The preparation of the consolidated financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect reported amounts and related disclosures. Specific areas, among others, requiring the application of management’s estimates and judgment include assumptions pertaining to the allowance for credit losses, valuation of deferred tax assets, valuation of derivative financial instruments, valuation of investments, valuation of certain long-term debt where the fair value option has been elected, valuation of pension and other employee benefits, and impairment of long-lived assets. During times of pandemics, such as COVID-19 Definition of cash and cash equivalents For purposes of the consolidated statements of cash flows, Cash and cash equivalents consists of Cash and due from banks and Interest-bearing deposits in other banks. Cash deposited with central banks that must be maintained to meet minimum regulatory requirements is classified as restricted cash and included in Cash and cash equivalents. See Note 8 “Pledged assets and collateral” for more information on restricted cash. Translation of foreign currency financial statements and foreign currency transactions Financial statements of overseas entities are prepared using the functional currency of each entity and translated into Japanese yen for consolidation purposes. Assets and liabilities are translated using the fiscal-year-end Foreign currency translation gains and losses related to the financial statements of overseas entities of the MHFG Group, net of related income tax effects, are credited or charged directly to Foreign currency translation adjustments, a component of Accumulated other comprehensive income (loss), net of tax (“AOCI”). The tax effects of gains and losses related to the foreign currency translation of financial statements of overseas entities are not recognized unless it is apparent that the temporary differences will reverse in the foreseeable future. Assets and liabilities of domestic and overseas entities denominated in foreign currencies are remeasured into the functional currency of the respective entity at the fiscal year-end Call loans and call money Call loans and call money represent lending/borrowing, primarily through the Japanese short-term money market, to/from other financial institutions such as banks, insurance companies, and securities brokerage houses. Repurchase and resale agreements, securities lending and borrowing and other secured financing transactions Securities sold under agreements to repurchase (“repurchase agreements”), securities purchased under agreements to resell (“resale agreements”) and securities lending and borrowing transactions are accounted for as secured financing or lending transactions when control over the underlying securities is not deemed to be surrendered by the transferor. Otherwise, they are recorded as sales of securities with related forward repurchase commitments or purchases of securities with related forward resale commitments in accordance with ASC 860, “Transfers and Servicing” (“ASC 860”). Under resale agreements, securities borrowing and certain derivatives transactions, the MHFG Group receives collateral in the form of securities. In many cases, the MHFG Group is permitted to sell or repledge the securities obtained as collateral. Disclosures in respect of such collateral are presented in Note 8 “Pledged assets and collateral.” With respect to repurchase agreements, securities lending, and certain derivative transactions, counterparties may have the right to sell or repledge securities that the MHFG Group has pledged as collateral. The MHFG Group separately discloses these pledged securities in the consolidated balance sheets. The MHFG Group monitors credit exposure arising from resale agreements, repurchase agreements, securities borrowing and securities lending transactions on a regular basis, and additional collateral is obtained from or returned to counterparties, as appropriate. Trading securities and trading securities sold, not yet purchased Trading securities consist of securities and money market instruments that are bought and held principally for the purpose of reselling in the near term with the objective of generating profits on short-term fluctuations in price. Trading securities sold, not yet purchased, are securities and money market instruments sold to third parties that the MHFG Group does not own and is obligated to purchase at a later date to cover the short position. Trading securities and trading securities sold, not yet purchased, are recorded on the trade date. Trading securities and trading securities sold, not yet purchased, are recorded at fair value in the consolidated balance sheets in Trading account assets and Trading account liabilities with realized and unrealized gains and losses recorded on a trade date basis in Trading account gains (losses)—net in the consolidated statements of income. Interest and dividends on trading securities, including securities sold, not yet purchased, are recorded in Interest and dividend income or Interest expense on an accrual basis. Investments Debt securities that the MHFG Group has both the positive intent and ability to hold to maturity are classified as Held-to-maturity Available-for-sale At the end of each reporting period the MHFG Group performs a review to identify impaired available-for-sale available-for-sale first-in first-out Other investments include marketable and non-marketable non-marketable Derivative financial instruments Derivative financial instruments are bought and held principally for the purpose of market making for customers, proprietary trading in order to generate trading revenues and fee income, and also to manage the MHFG Group’s exposure to interest rate, credit and market risks related to asset and liability management. Such derivative financial instruments include interest rate, foreign currency, equity, commodity and credit default swap agreements, options, caps and floors, and financial futures and forward contracts. Derivatives bought and held for trading purposes are recorded in the consolidated balance sheets at fair value in Trading account assets and Trading account liabilities. The fair values of derivatives in a gain position and a loss position are reported as Trading account assets and Trading account liabilities, respectively. Derivatives used for asset and liability management include contracts that qualify for hedge accounting under ASC 815, “Derivatives and Hedging” (“ASC 815”). To be eligible for hedge accounting, derivative instruments must be highly effective in achieving offsetting changes in fair values or variable cash flows of the hedged items attributable to the particular risk being hedged. All qualifying hedging derivatives are valued at fair value and included in Trading account assets or Trading account liabilities. Derivatives that do not qualify for hedge accounting under ASC 815 are treated as trading positions and are accounted for as such. The fair value amounts recognized for all derivatives are presented on a gross basis and not offset against the amounts recognized for the right to reclaim cash collateral or the obligation to return cash collateral under the master netting agreement with the same counterparty. The fair values of derivative financial instruments are determined based on quoted market prices or broker-dealer quotes, if available. If not available, the fair values are estimated using quoted market prices for similar instruments, option or binomial pricing models or a present value cash flow analysis, utilizing current observable market information, where available. In determining the fair values, the Group considers various factors such as exchange or over-the-counter Changes in the fair values of all derivatives are recorded in earnings, except for derivatives qualifying as net investment hedges under ASC 815 which are recorded in AOCI. The changes in the fair values of all derivatives relating to foreign currency exchange rates are included in Foreign exchange gains (losses)—net and Trading account gains (losses)—net. Other elements of the changes in the fair values, including interest rate, equity and credit related components, except these of certain credit derivatives hedging the credit risk in the corporate loan portfolio, are recognized in Trading account gains (losses)—net. The net gain (loss) resulting from changes in the fair values of certain credit derivatives where the Group purchases protection to mitigate its credit risk exposure related to its corporate loan portfolio is recorded in Other noninterest income (expenses). Certain financial and hybrid instruments often contain embedded derivative instruments that possess implicit or explicit contract terms similar to those of a derivative instrument. Such derivative instruments are required to be fair-valued separately from the host contracts if they meet the bifurcation criteria of an embedded derivative. Such criteria include that the entire instrument is not marked to market through earnings, the economic characteristics and risks of the embedded contract terms are not clearly and closely related to those of the host contract and the embedded contract terms would meet the definition of a derivative on a stand-alone basis. Loans Loans are generally carried at the principal amount adjusted for unearned income and deferred net nonrefundable loan fees and costs. Loan origination fees, net of certain direct origination costs, are deferred and recognized over the contractual life of the loan as an adjustment of yield using a method that approximates the interest method. Interest income on performing loans is accrued and credited to income as it is earned. Unearned income and discounts or premiums on purchased loans are deferred and recognized over the life of the loan using a method that approximates the interest method. Loans are considered nonaccrual when, based on current information and events, it is probable that the MHFG Group will be unable to collect all the scheduled payments of principal and interest when due according to the contractual terms of the loans. Factors considered by management in determining if a loan is nonaccrual include delinquency status and the ability of the debtor to make payments of the principal and interest when due. Nonaccrual loans include loans past due for 90 days or more and restructured loans that meet the definition of a troubled debt restructuring (“TDR”) in accordance with ASC 310, “Receivables” (“ASC 310”). The majority of nonaccrual loans have no contractual delinquency due to interest reductions and/or postponement of principal and interest. In March 2020, the Coronavirus, Aid, Relief, and Economic Security Act (“the CARES Act”) was approved. The CARES Act and U.S. banking agencies had among other items, provided optional, temporary relief related to accounting for certain TDRs. The temporary TDR relief was available to banks for loan modifications related to obligors who were adversely impacted by COVID-19. In case loans are designated as nonaccrual loans, interest accruals and the amortization of net origination fees are suspended and capitalized interest is written off. Cash received on nonaccrual loans is accounted for as a reduction of the loan principal if the ultimate collectability of the principal amount is in doubt, otherwise, as interest income. Loans are not restored to accrual status until interest and principal payments are current and future payments are reasonably assured. Nonaccrual loans are restored to accrual loans and accrual status, when the MHFG Group determines that the borrower poses no concerns regarding current certainty of debt fulfillment. In general, such determination is made if the borrower qualifies for an obligor rating of E2 or above and is not classified as a special attention obligor. With respect to loans restructured in a TDR, in general, such loans are restored to accrual loans, and accrual status, when the borrower qualifies for an obligor rating of D or above. See Note 4 “Loans” for the definitions of obligor ratings. Loans that have been identified for sale are classified as loans held for sale within Other assets and are accounted for at the lower of cost or fair value on an individual loan basis. If management decides to retain certain loans held for sale for the foreseeable future or until maturity or payoff, such items are transferred to Loans at the lower of cost or fair value. Financial instruments—current expected credit losses (“CECL”) The adoption of this guidance established a single allowance framework for all financial assets measured at amortized cost and certain off-balance-sheet available-for-sale the fiscal Allowance and provision (credit) for credit losses on loans Effective April 1, 2020, the allowance for credit losses on loans is established for current expected credit losses on the MHFG Group’s loan portfolio in accordance with ASC 326. Additionally, as of April 1, 2020, the Group did not elect the fair value option for financial assets measured at amortized cost basis. Prior to April 1, 2020, the allowance for credit losses on loans was established based on an incurred loss model in accordance with ASC 310 and ASC 450, “Contingencies” (“ASC 450”). The MHFG Group makes adjustments to the allowance for credit losses on loans through Provision (credit) for credit losses in the consolidated statements of income in each reporting period. Loan principal that management judges to be uncollectible, based on detailed loan reviews and a credit quality assessment, is charged off against the allowance for credit losses on loans. In general, the Group charges off loans when the Group determines that the obligor should be classified as substantially bankrupt or bankrupt. See Note 4 “Loans” for the definitions of obligor categories. Obligors in the retail portfolio segment are generally determined to be substantially bankrupt when they are past due for more than six months, and as for obligors in the corporate portfolio segment, the Group separately monitors the credit quality of each obligor without using time-based triggers. The MHFG Group maintains an appropriate allowance for credit losses on loans to represent management’s estimate of the expected credit losses in the Group’s loan portfolio. Management evaluates the appropriateness of the allowance for credit losses on loans semi-annually. The allowance considers expected credit losses over the remaining expected lives of the applicable instruments. The expected life of each instrument is determined by considering expected prepayments, contractual terms and cancellation features. The allowance for credit losses involves significant judgments on a number of matters including expectations of future economic conditions, assignment of obligor ratings, valuation of collateral, and the development of qualitative adjustments. When determining expected credit losses, a single forward-looking macroeconomic scenario is considered over a reasonable and supportable forecast period. This forward-looking macroeconomic scenario is in line with the scenario used for the Group’s business plan. If the scenario does not reflect a sudden change in economic conditions adequately, adjustments may be made to the scenario. After the forecast period, the Group reverts to long-term historical loss experience with a certain graduated transition period, to estimate losses over the remaining lives of financial assets measured at amortized cost and certain off-balance-sheet In terms of the internal risk ratings, for the corporate portfolio segment, the credit quality review process and the credit rating process serve as the basis for determining the allowance for credit losses on loans. Through such processes loans are categorized into groups to reflect the probability of default, whereby the MHFG Group’s management assesses the ability of borrowers to service their debt, taking into consideration current financial information, ability to generate cash, historical payment experience, analysis of relevant industry segments and current trends. For the retail portfolio segment, the different categories of past due status of loans are primarily utilized in the credit quality review and the credit rating processes as the basis for determining the allowance for credit losses on loans. In general, the MHFG Group estimates expected credit losses collectively on the loans in the case of normal and watch obligors, considering the risk associated with a particular pool and the probability that the exposures within the pool will deteriorate or default. The allowance for credit losses on nonaccrual loans includes the allowance for groups of loans which were collectively evaluated for expected credit losses, in addition to the allowance for those loans that were individually evaluated for expected credit losses. See Note 4 “Loans” for the definitions of obligor categories and classification of nonaccrual loans. The estimation of expected credit losses that are evaluated collectively begins with a quantitative calculation that considers the likelihood of the borrower changing delinquency status or moving from one obligor category or rating to another. The quantitative calculation covers expected credit losses over an instrument’s expected life and is estimated by applying credit loss factors to the MHFG Group’s estimated exposure at default. The credit loss factors incorporate the probability of default as well as the loss given default based on the historical loss rates. To supplement the historical loss data for overseas obligors, external credit ratings such as S&P are also used to calculate the probability of default. The model and inputs used to determine credit losses on loans that are evaluated collectively are analyzed on a periodic basis by comparing the estimated values with the actual results subsequent to the balance sheet date. The MHFG Group divides its overall portfolio into domestic and foreign portfolios and categorizes the domestic portfolio into four portfolio segments according to their risk profiles: corporate, retail, sovereign, and banks and financial institutions. The corporate portfolio segment consists of loans originated primarily by MHBK and MHTB, and includes mainly business loans such as those used for working capital and capital expenditure, as well as loans for which the primary source of repayment of the obligation is income generated by the relevant assets such as project finance, asset finance and real estate finance. The corporate portfolio segment is divided into two classes based on their risk characteristics: large companies, and small and medium-sized The retail portfolio segment consists mainly of residential mortgage loans originated by MHBK, and it is divided into two classes based on their risk characteristics: housing loan and others. For the retail portfolio segment, the Japanese unemployment rate is applied as a key factor. As it pertains to TDRs in the retail portfolio segment, the restructuring itself, as well as subsequent payment defaults, if any, are considered in determining obligor categories. Expected credit loss estimates also include consideration of expected cash recoveries on loans previously charged-off, The allowance recorded for individually evaluated loans is based on (1) the present value of expected future cash flows, after considering the restructuring effect and subsequent payment default with respect to TDRs, discounted at the loan’s initial effective interest rate, (2) the loan’s observable market price, or (3) the fair value of the collateral if the loan is collateral dependent. The collateral that the MHFG Group obtains for loans consists primarily of real estate. In obtaining the collateral, the Group evaluates the fair value of the collateral and its legal enforceability. The Group also performs subsequent re-evaluations The MHFG Group’s methodology for determining the appropriate allowance for credit losses on loans also considers the imprecision inherent in the methodologies used. As a result, the amounts determined under the methodologies described above could be adjusted by management to consider the potential impact of other qualitative factors which include, but are not limited to, imprecision in macroeconomic scenario assumptions and emerging risks related to changes in the environment that are affecting specific portfolio segments including segments impacted by the Russia-Ukraine situation. Considering internal and external factors affecting the credit quality of the portfolio, the Group incorporated the estimated impact of COVID-19 Russia-Ukraine In terms of the Russia-Ukraine situation, considering the country risk arising from the sanctions against Russia and the downgrading of their credit rating, as well as the risk of deterioration in the global economy due to inflation caused by soaring energy prices and the acceleration of supply chain disruptions caused by the withdrawal of operations from Russia, the MHFG Group incorporated an estimate of the Russia-Ukraine situation into the macroeconomic scenario used for determining the allowance for credit losses on loans. Allowance and provision (credit) for credit losses on off-balance-sheet The MHFG Group maintains an allowance for credit losses on off-balance-sheet off-balance-sheet off-balance-sheet Allowance and provision (credit) for credit losses on available-for-sale The MHFG Group performs periodic reviews to identify impaired securities in accordance with ASC 326. Available-for-sale available-for-sale available-for-sale available-for-sale available-for-sale Premises and equipment Premises and equipment are stated at historical cost, and depreciation and amortization are recorded over the estimated useful lives of the assets, except for leasehold improvements, which are amortized over the shorter of the estimated useful lives of the assets or the lease term. Depreciation and amortization are principally computed in accordance with the straight-line method with respect to buildings and leasehold improvements and in accordance with the declining-balance method with respect to other premises and equipment. The useful lives of premises and equipment are as follows: Years Buildings 3 to 50 Equipment and furniture 2 to 20 Regular repairs and maintenance costs that do not extend the estimated useful life of an asset are charged to expense as incurred. Upon sale or disposition of premises and equipment, the cost and related accumulated depreciation or amortization are removed from the accounts, and any gains or losses on disposal are included in Gains on disposal of premises and equipment or Occupancy expenses. Impairment of long-lived assets The MHFG Group’s long-lived assets that are held for use are reviewed periodically for events or changes in circumstances that indicate possible impairment. The Group’s impairment review is based on an undiscounted cash flow analysis of a group of assets, combined with associated liabilities, at the lowest level for which identifiable cash flows exist. Impairment occurs when the carrying value of the asset group exceeds the future undiscounted cash flows that the asset group is expected to generate. When impairment is identified, the future cash flows are then discounted to determine the estimated fair value of the asset group and an impairment charge is recorded for the difference between the carrying value and the estimated fair value of the asset group. The long-lived assets to be disposed of by sale are carried at the lower of the carrying amount or fair value, less estimated cost to sell. Software Internal and external costs incurred in connection with developing and obtaining software for internal use during the application development stage are capitalized. Such costs include salaries and benefits for employees directly involved with and who devote time to the project, to the extent such time is incurred directly on the internal use software project. The capitalization of software ceases when the software project has been substantially completed. The capitalized software is amortized on a straight-line basis over the estimated useful life, generally 5 to 10 years. Internal use software is reviewed for impairment whenever events or changes in circumstances indicate that its carrying amount may not be recoverable. Goodwill Goodwill represents the excess of the total fair value of the acquired company, which consists of the consideration transferred, the fair value of any interest in the acquiree already held by the acquirer and the fair value of any noncontrolling interest in the acquiree over the fair value of net identifiable assets acquired at the date of acquisition in a business combination. The MHFG Group accounts for goodwill in accordance with ASC 350, “Intangibles—Goodwill and Other” (“ASC 350”). Goodwill is recorded at a designated reporting unit level for the purpose of assessing impairment. Goodwill is not amortized but is tested for impairment at least annually or more often if events or circumstances indicate there may be impairment. For both the annual and interim tests, the Group has the option to either (a) perform a quantitative impairment test or (b) first perform a qualitative assessment to determine whether it is more likely than not that the fair value of a reporting unit is less than its carrying amount, in which case the Group would perform the quantitative test. An impairment loss is recorded to the extent the carrying amount of goodwill exceeds its estimated fair value. The estimated fair value of the reporting units is derived based on valuation techniques that the Group believes market participants would use for each of the reporting units. The Group generally determines the estimated fair value by utilizing a discounted cash flow methodology or methodologies that incorporate price-to-book Intangible assets Intangible assets having definite useful lives are amortized over their estimated useful lives on either a straight-line Leases The MHFG Group, as a lessee, recognizes liabilities to make lease payments and right-of-use extend or terminate the lease that the Group is reasonably certain to exercise. The Group uses its incremental borrowing rates at the lease commencement to determine the lease liability, which is measured at the present value of future lease payments, when the rate implicit in the lease is not readily determinable. The Group has elected not to separate lease and non-lease right-of-use right-of-use right-of-use right-of-use Pension and other employee benefits MHFG and certain subsidiaries sponsor pension plans which provide defined benefits to retired employees and other postretirement benefit plans, including severance indemnities. Severance indemnities are amounts payable to eligible employees upon termination of employment and are payable as a lump sum. Periodic expense and accrued liabilities are computed based on the actuarial present value of benefits, net of investment returns expected from plan assets and their fair values at the balance sheet date. Net periodic expense is charged to Salaries and employee benefits. Net actuarial gains and losses that arise from differences between actual experience and assumptions are generally amortized over the average remaining service period of participating employees if they exceed the corridor, which is defined as the greater of 10% of plan assets or the projected benefit obligation. Stock-based compensation MHFG, MHBK, MHTB and MHSC have a responsibility-based stock compensation program for Directors (“Stock Compensation I”) and a performance-based stock compensation program for Directors (“Stock Compensation II”). MHFG and certain consolidated subsidiaries introduced both responsibility-based and performance-based stock compensation program for Operating Officers (“Stock Benefit”) in July 2021. For these programs, the stock-based compensation cost is determined based on the fair value of MHFG’s common stock as of grant date. The liability related to the cash-based compensation cost is remeasured at each reporting date based on the fair value of MHFG’s common stock. For Stock Compensation I, as the program is effectively vested on the grant date, the stock-based compensation cost is recognized on the grant date. For Stock Compensation II, the stock-based compensation costs are recognized evenly over the graded-vesting period, which is three years. For Stock Benefit, the stock-based compensation costs are recognized evenly over the vesting period, which is one year. See Note 21 “Stock-based compensation” for further details of the stock options and the stock compensation programs. Long-term debt Premiums, discounts and issuance costs of long-term debt are amortized based on a method that approximates the interest method over the respective terms of the long-term debt. Obligations under guarantees The MHFG Group provides customers with a variety of guarantees and similar arrangements, including standby letters of credit, financial and performance guarantees, credit protection, and liquidity facilities. The MHFG Group recognizes guarantee fee income over the guarantee period. The MHFG Group receives such a guarantee fee at the inception of the guarantee or in installments and, in either case, the present value of the total fees approximates the fair value of the guarantee. Fair Value Measurements The MHFG

Issued accounting pronouncement

Issued accounting pronouncements	12 Months Ended
	Mar. 31, 2022
Issued accounting pronouncements	2. Issued accounting pronouncements Adopted accounting pronouncements In March 2020, the FASB issued ASU No.2020-04, No.2020-04”). No.2021-01, No.2021-01”). No.2020-04 No.2021-01 Accounting pronouncements issued but not yet effective as of March 31, 2022 In March 2022, the FASB issued ASU No.2022-02, No.2022-02”). 310-40, 310-20-35-9 35-11 No.2022-02

Investments

Investments	12 Months Ended
	Mar. 31, 2022
Investments	3. Investments Available-for-sale held-to-maturity The amortized cost, net of allowance for credit losses, gross unrealized gains and losses, and fair value of available-for-sale held-to-maturity Amortized (4)(5) Gross gains Gross losses Fair value ( in millions of yen 2021 Available-for-sale Debt securities: Japanese government bonds 20,953,200 1,945 34,562 20,920,583 Japanese local government bonds 463,673 544 658 463,559 U.S. Treasury bonds and federal agency securities 906,499 4,440 46 910,893 Other foreign government bonds 1,505,770 1,975 209 1,507,536 Agency mortgage-backed securities (1) 512,720 8,746 687 520,779 Residential mortgage-backed securities 70,111 761 188 70,684 Commercial mortgage-backed securities 709,938 6,196 39 716,095 Japanese corporate bonds and other debt securities 1,897,117 10,537 3,574 1,904,080 Foreign corporate bonds and other debt securities (2) 837,675 2,577 1,426 838,826 Total 27,856,703 37,721 41,389 27,853,035 Held-to-maturity Debt securities: Japanese government bonds 479,959 9,555 — 489,514 Agency mortgage-backed securities (3) 407,190 10,178 3,273 414,095 Total 887,149 19,733 3,273 903,609 Amortized (4)(5) Gross gains Gross losses Fair value ( in millions of yen 2022 Available-for-sale Debt securities: Japanese government bonds 25,191,315 5,794 38,379 25,158,730 Japanese local government bonds 421,557 254 2,165 419,646 U.S. Treasury bonds and federal agency securities 381,653 — 8,444 373,209 Other foreign government bonds 1,338,295 220 2,578 1,335,937 Agency mortgage-backed securities (1) 452,830 1,695 3,985 450,540 Residential mortgage-backed securities 58,246 194 312 58,128 Commercial mortgage-backed securities 848,568 5,437 214 853,791 Japanese corporate bonds and other debt securities 2,222,670 14,212 1,705 2,235,177 Foreign corporate bonds and other debt securities (2) 787,263 2,490 1,021 788,732 Total 31,702,397 30,296 58,803 31,673,890 Held-to-maturity Debt securities: Japanese government bonds 479,980 5,101 — 485,081 Agency mortgage-backed securities (3) 1,039,075 24 58,604 980,495 Total 1,519,055 5,125 58,604 1,465,576 Notes: (1) Agency mortgage-backed securities presented in this line consist of Japanese and Foreign agency mortgage-backed securities, of which the fair values were ¥520,746 million and ¥33 million, respectively, at March 31, 2021, and ¥450,507 million and ¥33 million, respectively, at March 31, 2022. All Japanese agency mortgage-backed securities are issued by Japan Housing Finance Agency, a Japanese government-sponsored enterprise. Foreign agency mortgage-backed securities primarily consist of Government National Mortgage Association (“Ginnie Mae”) securities, which are guaranteed by the United States government. (2) Other debt securities presented in this line primarily consist of Foreign negotiable certificates of deposit (“NCDs”) and asset-backed securities (“ABS”), of which the total fair values were ¥275,661 million at March 31, 2021, and ¥247,762 million at March 31, 2022. (3) All Agency mortgage-backed securities presented in this line are Ginnie Mae securities. (4) Amortized cost, net of the allowance for credit losses, of which the amounts related to available-for-sale (5) Accrued interest receivables are excluded from amortized cost, of which the amount were ¥10,379 million at March 31, 202 1 Contractual maturities The amortized cost, net of allowance for credit losses, and fair value of available-for-sale held-to-maturity Amortized cost Due in one year or less Due after one year through five years Due after five years through ten years Due after ten years Total (in millions of yen) Available-for-sale Debt securities: Japanese government bonds 19,242,514 4,160,143 1,681,312 107,346 25,191,315 Japanese local government bonds 27,258 220,168 166,619 7,512 421,557 U.S. Treasury bonds and federal agency securities 82,287 299,366 — — 381,653 Other foreign government bonds 1,066,461 269,579 1,129 1,126 1,338,295 Agency mortgage-backed securities — — — 452,830 452,830 Residential mortgage-backed securities — — — 58,246 58,246 Commercial mortgage-backed securities 30,000 444,413 374,155 — 848,568 Japanese corporate bonds and other debt securities 154,142 1,275,410 277,228 515,890 2,222,670 Foreign corporate bonds and other debt securities 452,173 186,434 130,201 18,455 787,263 Total 21,054,835 6,855,513 2,630,644 1,161,405 31,702,397 Held-to-maturity Debt securities: Japanese government bonds 100,023 379,957 — — 479,980 Agency mortgage-backed securities — — — 1,039,075 1,039,075 Total 100,023 379,957 — 1,039,075 1,519,055 Fair value Due in one year or less Due after one year through five years Due after five years through ten years Due after ten years Total (in millions of yen ) Available-for-sale Debt securities: Japanese government bonds 19,241,161 4,151,094 1,663,395 103,080 25,158,730 Japanese local government bonds 27,279 219,972 164,987 7,408 419,646 U.S. Treasury bonds and federal agency securities 81,742 291,467 — — 373,209 Other foreign government bonds 1,065,814 267,868 1,129 1,126 1,335,937 Agency mortgage-backed securities — — — 450,540 450,540 Residential mortgage-backed securities — — — 58,128 58,128 Commercial mortgage-backed securities 30,004 446,606 377,181 — 853,791 Japanese corporate bonds and other debt securities 154,196 1,276,212 278,697 526,072 2,235,177 Foreign corporate bonds and other debt securities 451,918 186,739 130,548 19,527 788,732 Total 21,052,114 6,839,958 2,615,937 1,165,881 31,673,890 Held-to-maturity Debt securities: Japanese government bonds 100,650 384,431 — — 485,081 Agency mortgage-backed securities — — — 980,495 980,495 Total 100,650 384,431 — 980,495 1,465,576 Credit losses The MHFG Group recognized no material allowance for credit loss on available-for-sale available-for-sale a n billion on April 1, 2021. The increase was due mainly to a n held-to-maturity Continuous unrealized loss position The following table shows the gross unrealized losses, net of allowance for credit losses, and fair value of available-for-sale Less than 12 months 12 months or more Total Fair value Gross unrealized losses Fair value Gross unrealized losses Fair value Gross unrealized losses (in millions of yen) 2021 Available-for-sale Debt securities: Japanese government bonds 9,998,772 1,924 4,058,718 32,638 14,057,490 34,562 Japanese local government bonds 125,058 323 130,384 335 255,442 658 U.S. Treasury bonds and federal agency securities 38,625 46 — — 38,625 46 Other foreign government bonds 576,415 209 — — 576,415 209 Agency mortgage-backed securities (Note) 70,088 120 36,989 567 107,077 687 Residential mortgage-backed securities 9,270 52 11,435 136 20,705 188 Commercial mortgage-backed securities 12,530 6 10,351 33 22,881 39 Japanese corporate bonds and other debt securities 278,698 953 843,026 2,621 1,121,724 3,574 Foreign corporate bonds and other debt securities 233,405 1,426 — — 233,405 1,426 Total 11,342,861 5,059 5,090,903 36,330 16,433,764 41,389 2022 Available-for-sale Debt securities: Japanese government bonds 19,407,878 11,377 1,565,950 27,002 20,973,828 38,379 Japanese local government bonds 229,562 1,277 136,733 888 366,295 2,165 U.S. Treasury bonds and federal agency securities 321,073 7,209 41,555 1,235 362,628 8,444 Other foreign government bonds 729,134 2,178 71,647 400 800,781 2,578 Agency mortgage-backed securities (Note) 183,150 2,326 78,717 1,659 261,867 3,985 Residential mortgage-backed securities 9,221 11 17,193 301 26,414 312 Commercial mortgage-backed securities 58,815 185 13,939 29 72,754 214 Japanese corporate bonds and other debt securities 605,067 1,516 53,020 189 658,087 1,705 Foreign corporate bonds and other debt securities 302,569 692 53,338 329 355,907 1,021 Total 21,846,469 26,771 2,032,092 32,032 23,878,561 58,803 Note: Agency mortgage-backed securities presented in this line consist of Japanese agency mortgage-backed securities, of which the fair values were ¥107,077 million at March 31, 2021, and ¥261,867 million at March 31, 2022. All Japanese agency mortgage-backed securities are issued by Japan Housing Finance Agency, a Japanese government-sponsored enterprise. At March 31, 2022, the MHFG Group did not intend to sell the debt securities in an unrealized loss position and it was not more likely than not that the MHFG Group would be required to sell them before the recovery of their amortized cost bases. For Japanese government bonds, U.S. Treasury bonds and federal agency securities and Agency mortgage-backed securities, their entire amortized cost bases were expected to be recovered since the unrealized losses had not resulted from credit deterioration, but primarily from changes in interest rates. For the debt securities other than those described above, except for the securities for which credit losses have been recognized in income, the MHFG Group determined that their entire amortized cost bases were expected to be recovered, after considering various factors such as the extent to which their fair values were below their amortized cost bases, the external and/or internal ratings and the present values of cash flows expected to be collected. Based on the aforementioned evaluation, except for the securities for which credit losses have been recognized in income, the MHFG Group determined that the debt securities in an unrealized loss position were not considered credit losses. Realized gains and losses The following table shows the realized gains and losses on sales of available-for-sale 2020 2021 2022 (in millions of yen) Gross realized gains 41,903 3,309 12,540 Gross realized losses (13,398 ) (24,407 ) (40,077 ) Net realized gains (losses) on sales of available-for-sale 28,505 (21,098 ) (27,537 ) Equity securities Equity securities include securities which have readily determinable fair values, securities which qualify for the practical expedient to estimate fair value using the net asset value per share (or its equivalent), and securities which are without readily determinable fair values. Equity securities which have readily determinable fair values mainly consist of common stock of Japanese listed companies. Equity securities which are measured based on the net asset value per share (or its equivalent) consist of private equity and real estate funds. Equity securities without readily determinable fair values include non-marketable Net gains and losses The following table shows the details of the net gains and losses on Equity securities for the fiscal years ended March 31, 2020, 2021 and 2022: 2020 2021 2022 (in millions of yen) Net gains (losses) recognized during the period on equity securities (557,391 ) 850,567 (60,563 ) Less: Net gains (losses) recognized during the period on equity securities sold during the period 1,710 82,969 17,000 Unrealized gains (losses) recognized during the reporting period on equity securities still held at the reporting period (559,101 ) 767,598 (77,563 ) Equity securities without readily determinable fair values The following table shows carrying amounts of equity securities without readily determinable fair values, for which the measurement alternative is used, and cumulative amounts due to downward adjustments and impairments and upward adjustments, at March 31, 2020, 2021 and 2022: 2020 2021 2022 (in millions of yen) Carrying amounts at the end of the period 419,775 186,146 207,407 Downward adjustments and impairments 2,435 5,087 6,519 Upward adjustments 9,128 9,216 11,623 The following table shows amounts recognized in earnings during the period due to downward adjustments and impairments and upward adjustments for equity securities without readily determinable fair values. 2020 2021 2022 (in millions of yen) Downward adjustments and impairments 1,272 3,084 2,626 Upward adjustments 6,928 404 2,459 The MHFG Group elected to measure all equity securities without readily determinable fair values, which do not qualify for the practical expedient to estimate fair value, using the measurement alternative, which is made on an instrument-by-instrument Other investments The following table summarizes the composition of Other investments at March 31, 2021 and 2022: 2021 2022 (in millions of yen) Equity method investments 460,025 519,552 Investments held by consolidated investment companies and other 55,321 62,836 Total 515,346 582,388 Equity method investments Investments in investees over which the MHFG Group has the ability to exert significant influence are accounted for using the equity method of accounting. Such investments included marketable equity securities with carrying values of ¥229,156 million and ¥255,336 million, at March 31, 2021 and 2022, respectively. The aggregate market values of these marketable equity securities were ¥424,267 million and ¥456,195 million, respectively. The majority of aggregate market values of these marketable equity securities include Orient Corporation, the Chiba Kogyo Bank, Ltd., Joint Stock Commercial Bank for Foreign Trade of Vietnam and Mizuho Leasing Company, Limited of which the MHFG Group’s proportionate share of the total outstanding common stock w ere 16.89%, 15.00% and 23.49%, respectively, as of March 31, 2022. In addition, equity method investments include non-marketable ere Investments held by consolidated investment companies The MHFG Group consolidates certain investment companies over which it has control through either ownership or other means. Investment companies are subject to specialized industry accounting which requires investments to be carried at fair value, with changes in fair value recorded in earnings. The MHFG Group maintains this specialized industry accounting for investments held by consolidated investment companies, which consist of marketable and non-marketable

Loans

Loans	12 Months Ended
	Mar. 31, 2022
Loans	4. Loans Credit quality information In accordance with the MHFG Group’s credit risk management policies, the Group uses an internal rating system that consists of credit ratings for the corporate portfolio segment and pool allocations for the retail portfolio segment as the basis of its risk management infrastructure. Credit ratings consist of obligor ratings which represent the level of credit risk of the obligor, and transaction ratings which represent the ultimate possibility of losses expected on individual loans by taking into consideration various factors such as collateral or guarantees involved. In principle, obligor ratings are applied to all obligors except those to which pool allocations are applied, and are subject to regular review at least once a year as well as special review which is required whenever the obligor’s credit standing changes. Pool allocations are applied to small loans that are less than a specified amount by pooling customers and loans with similar risk characteristics, and the risk is assessed mainly based on past due status and managed according to such pools. The Group generally reviews the appropriateness and effectiveness of the approach to obligor ratings and pool allocations once a year in accordance with predetermined policies and procedures. The Group does not record expected credit losses for accrued interest receivables because uncollectible accrued interest is reversed through interest income in a timely manner in line with the Group’s nonaccrual and past due policies for loans. The amount of accrued interest receivables was ¥77,764 million and ¥80,959 million at March 31, 2021 and 2022, respectively and included in Accrued income. The Group does not believe that its exposure to any particular geographic area and business sector results in a significant concentration of credit risk. The table below presents the MHFG Group’s definition of obligor ratings used by MHBK and MHTB, and equivalent obligor ratings are determined for the other subsidiaries: Obligor category (1) (2) Obligor rating Definition Normal A Obligors whose certainty of debt fulfillment is very high, hence their level of credit risk is very low. B Obligors whose certainty of debt fulfillment poses no problems for the foreseeable future, and their level of credit risk is low. C Obligors whose certainty of debt fulfillment and their level of credit risk pose no problems for the foreseeable future. D Obligors whose current certainty of debt fulfillment poses no problems, however, their resistance to future economic environmental changes is low. Watch E1 Obligors that require observation going forward because of either minor concerns regarding their financial position, or their somewhat weak or unstable business conditions. E2 Obligors that require special observation going forward because of problems with their borrowings such as reduced or suspended interest payments, problems with debt fulfillment such as failure to make principal or interest payments, or problems with their financial position as a result of their weak or unstable business conditions. Intensive control F Obligors that are not yet bankrupt but are in financial difficulties and are deemed likely to become bankrupt in the future because of insufficient progress in implementing their management improvement plans or other measures (including obligors that are receiving ongoing support from financial institutions). Substantially bankrupt G Obligors that have not yet become legally or formally bankrupt but are substantially insolvent because they are in serious financial difficulties and are deemed to be incapable of being restructured. Bankrupt H Obligors that have become legally or formally bankrupt. Notes: (1) Special attention obligors are watch obligors with debt in TDR or 90 days or more delinquent debt. Loans to such obligors are considered nonaccrual. (2) The Group classifies loans to special attention, intensive control, substantially bankrupt and bankrupt obligors as nonaccrual loans. The table below pres e Term loans by origination year 2020 2019 2018 2017 2016 Prior to Revolving Loans Total (in millions of yen) 2021 Domestic: Corporate: Large companies: Normal obligors 14,351,596 6,173,182 6,884,219 2,384,565 2,105,541 2,256,613 6,819,851 40,975,567 Watch obligors excluding special attention obligors 151,406 86,390 86,199 61,785 40,907 35,681 128,363 590,731 Nonaccrual loans 219,111 196,945 38,490 129,066 28,650 9,547 194,607 816,416 Small and medium-sized Normal obligors 633,438 463,744 397,656 224,791 205,687 502,707 518,612 2,946,635 Watch obligors excluding special attention obligors 62,300 24,245 30,007 13,547 13,536 24,430 29,041 197,106 Nonaccrual loans 78,238 10,794 7,341 5,168 3,154 8,852 28,853 142,400 Retail: Housing Loan: Normal obligors 785,194 588,599 588,535 600,179 741,969 4,599,546 — 7,904,022 Watch obligors excluding special attention obligors 2,041 1,075 1,566 1,343 2,127 39,046 — 47,198 Nonaccrual loans 20,706 2,268 1,399 1,421 1,640 35,135 — 62,569 Others: Normal obligors 431,277 154,675 127,379 88,649 85,042 317,237 526,703 1,730,962 Watch obligors excluding special attention obligors 50,212 14,288 10,450 5,888 3,713 5,796 10,545 100,892 Nonaccrual loans 32,594 2,086 1,145 901 837 8,780 12,557 58,900 Sovereign: Normal obligors 1,466,468 80,260 128,702 71,943 75,389 389,777 12,615 2,225,154 Watch obligors excluding special attention obligors 4,312 3,594 2,164 635 31 — — 10,736 Nonaccrual loans — — — — — — — — Banks and other financial institutions : Normal obligors 51,874 135,135 241,418 24,097 84,244 60,281 162,622 759,671 Watch obligors excluding special attention obligors — — — — — — — — Nonaccrual loans — — — — — — — — Total domestic 18,340,767 7,937,280 8,546,670 3,613,978 3,392,467 8,293,428 8,444,369 58,568,959 Foreign: Corporate (4) : Normal obligors 12,813,813 4,614,310 2,558,432 922,526 655,823 1,143,658 4,501,155 27,209,717 Watch obligors excluding special attention obligors 196,054 36,915 72,529 54,514 894 25,009 127,553 513,468 Nonaccrual loans 61,657 29,657 12,547 3,034 4,417 17,394 14,580 143,286 Retail: Normal obligors 2,100 2,342 1,468 1,034 1,074 1,401 18 9,437 Watch obligors excluding special attention obligors — — — 14 — 13 — 27 Nonaccrual loans — — — — — — — — Sovereign: Normal obligors 96,177 78,727 26,569 157,256 — 4,474 69,320 432,523 Watch obligors excluding special attention obligors — — — — — 20,118 — 20,118 Nonaccrual loans — 710 — — — — — 710 Banks and other financial institutions : Normal obligors 1,030,080 317,635 275,695 18,272 1,497 3,105 25,145 1,671,429 Watch obligors excluding special attention obligors 6,341 — 78 — 4,774 — — 11,193 Nonaccrual loans — — — — — — — — Total foreign 14,206,222 5,080,296 2,947,318 1,156,650 668,479 1,215,172 4,737,771 30,011,908 Total 32,546,989 13,017,576 11,493,988 4,770,628 4,060,946 9,508,600 13,182,140 88,580,867 Term loans by origination year 2021 2020 2019 2018 2017 Prior to Revolving Loans Total (in millions of yen) 2022 Domestic: Corporate: Large companies: Normal obligors 12,236,438 6,640,211 5,049,408 4,535,083 1,678,591 3,378,926 7,155,041 40,673,698 Watch obligors excluding special attention obligors 145,167 69,404 71,937 66,122 40,205 50,499 127,319 570,653 Nonaccrual loans 60,525 100,975 201,375 44,919 135,777 77,602 178,416 799,589 Small and medium-sized Normal obligors 540,315 396,611 376,056 283,061 170,952 494,420 547,726 2,809,141 Watch obligors excluding special attention obligors 44,488 31,196 29,597 31,919 12,231 32,511 25,277 207,219 Nonaccrual loans 17,866 20,110 14,434 10,817 7,081 38,171 32,081 140,560 Retail: Housing Loan: Normal obligors 798,354 544,246 518,662 526,828 543,893 4,752,430 — 7,684,413 Watch obligors excluding special attention obligors 1,512 1,485 1,510 1,939 1,226 40,243 — 47,915 Nonaccrual loans 12,510 3,132 802 1,180 970 30,598 — 49,192 Others: Normal obligors 195,545 277,015 111,702 90,880 60,919 315,375 497,173 1,548,609 Watch obligors excluding special attention obligors 23,586 34,974 10,177 7,995 4,122 6,388 9,491 96,733 Nonaccrual loans 6,932 7,862 3,157 4,253 4,076 22,951 12,602 61,833 Sovereign: Normal obligors 938,534 105,966 89,385 108,664 54,580 351,876 1,864 1,650,869 Watch obligors excluding special attention obligors 3,933 4,205 859 366 113 — — 9,476 Nonaccrual loans — — — — — — — — Banks and other financial institutions : Normal obligors 45,825 23,757 131,932 211,445 3 143,717 125,078 681,757 Watch obligors excluding special attention obligors — — — — — — — — Nonaccrual loans — — — — — — — — Total dom e 15,071,530 8,261,149 6,610,993 5,925,471 2,714,739 9,735,707 8,712,068 57,031,657 Foreign: Corporate (4) : Normal obligors 14,087,409 3,571,416 3,236,191 1,392,231 550,082 1,228,924 5,906,045 29,972,298 Watch obligors excluding special attention obligors 316,387 179,555 73,656 55,876 28,325 25,384 122,410 801,593 Nonaccrual loans 35,801 1,622 13,743 17,181 14,743 22,639 9,745 115,474 Retail: Normal obligors 2,403 1,774 1,858 1,013 532 3,089 15 10,684 Watch obligors excluding special attention obligors — — 37 — — 13 — 50 Nonaccrual loans — — — — — — — — Sovereign: Normal obligors 278,373 6,856 33,225 15,194 174,298 3,079 74,923 585,948 Watch obligors excluding special attention obligors — — — — — — — — Nonaccrual loans — — 643 — — — — 643 Banks and other financial institutions : Normal obligors 1,003,709 254,232 150,505 224,571 12,041 709 120,088 1,765,855 Watch obligors excluding special attention obligors 5,544 — — — — — — 5,544 Nonaccrual loans 837 — — — — — — 837 Total foreign 15,730,463 4,015,455 3,509,858 1,706,066 780,021 1,283,837 6,233,226 33,258,926 Tota l 30,801,993 12,276,604 10,120,851 7,631,537 3,494,760 11,019,544 14,945,294 90,290,583 Notes: (1) Special attention obligors are watch obligors with debt in TDR or 90 days or more delinquent debt. Loans to such obligors are considered nonaccrual. (2) The primary component of the retail portfolio segment is housing loans to individuals which obligor category is classified based on past due status. The trigger to reclassify obligors from normal obligors to watch obligors excluding special attention obligors is when the past due status is more than 30 days. (3) There were no significant revolving line of credit arrangements that converted to term loans during the fiscal year ended March 31, 2021 and (4) Corporate of foreign includes ¥221,908 million and ¥216,463 Nonaccrual loans The MHFG Group considers loans to be nonaccrual when it is probable that the Group will be unable to collect all the scheduled payments of principal and interest when due according to the contractual terms of the loans. The Group classifies loans to special attention, intensive control, substantially bankrupt and bankrupt obligors as nonaccrual loans. There are no loans that are 90 days past due and still accruing. The Group does not have any loans to borrowers that cause management to have serious doubts as to the ability of such borrowers to comply with the present loan repayment terms for the periods presented other than those already designated as nonaccrual loans. The table below presents nonaccrual loans information at March 31, 2021 and 2022: Amortized cost Interest income recognized Nonaccrual loans with an allowance Nonaccrual loans without an allowance Total nonaccrual loans (in millions of yen) 2021 Domestic: Corporate: Large companies 800,329 16,087 816,416 13,050 Small and medium-sized 121,031 21,369 142,400 1,759 Retail: Housing Loan 37,006 25,563 62,569 1,073 Others 37,884 21,016 58,900 806 Total domestic 996,250 84,035 1,080,285 16,688 Foreign: Total foreign 117,300 26,696 143,996 2,422 Total 1,113,550 110,731 1,224,281 19,110 2022 Domestic: Corporate: Large companies 783,305 16,284 799,589 9,426 Small and medium-sized 121,598 18,962 140,560 1,700 Retail: Housing Loan 26,812 22,380 49,192 946 Others 40,155 21,678 61,833 819 Total domestic 971,870 79,304 1,051,174 12,891 Foreign: Total foreign 110,284 6,670 116,954 1,469 Total 1,082,154 85,974 1,168,128 14,360 Notes: (1) Amounts represent the outstanding balances of nonaccrual loans. The MHFG Group’s policy for placing loans in nonaccrual status corresponds to the Group’s definition of nonaccrual loans. (2) Amounts represent the amount of interest income on nonaccrual loans recognized on a cash basis and included in Interest income on loans in the consolidated statements of income. (3) The majority of total foreign consist of corporate. The remaining balance of nonaccrual loans that have been partially charged off, was ¥20,197 million and ¥13,046 million as of March 31, 2021 and 2022, respectively. Troubled debt restructurings The MHFG Group considers a loan modification to be a TDR when, for economic or legal reasons related to the obligor’s financial difficulties, it grants a concession to the obligor that it would not otherwise consider. The Group considers the relevant obligor to be in financial difficulty generally when its obligor rating is E2 or below. The following table presents modified loans that were determined to be TDRs during the fiscal years ended March 31, 2021 and 2022: Loan forgiveness or debt to equity swaps Interest rate reduction and/or postponement of principal and/or interest Recorded investment (1) Charge-offs (in millions of yen) 2021 Domestic: Corpora t Large companies — 160 597,281 Small and medium-sized — — 120,798 Retail: Housing Loan — — 21,548 Others — — 20,604 Banks and other financial institutions — — 3,200 Total domestic — 160 763,431 Foreign: Total foreign 2,614 4,385 163,149 Total 2,614 4,545 926,580 2022 Domestic: Corporate: Large companies 5,849 22,757 612,569 Small and medium-sized — — 125,103 Retail: Housing Loan — — 7,897 Others — — 21,749 Total domestic 5,849 22,757 767,318 Foreign: Total foreign — — 62,651 Total 5,849 22,757 829,969 Notes: (1) Amounts represent the book values of loans immediately after the restructurings. (2) The majority of total foreign consist of corporate. Payment default is deemed to occur when the loan becomes three months past due or the obligor is downgraded to the category of substantially bankrupt or bankrupt. The following table presents payment defaults which occurred during the fiscal years ended March 31, 2021 and 2022 with respect to the loans modified as TDRs within the previous twelve months: Recorded investment 2021 2022 (in millions of yen) Domestic: Corporate: Large companies 10,590 7,831 Small and medium-sized 5,603 2,777 Retail: Housing Loan 810 938 Others 2,133 1,000 Total domestic 19,136 12,546 Foreign: Total foreign 47,239 14,126 Total 66,375 26,672 Age analysis of past due loans The table below presents an analysis of the age of the amortized cost basis in loans that are past due at March 31, 2021 and 2022: 30-59 days past due 60-89 days past due 90 days or more past due Total past due Current Total (in millions of yen) 2021 Domestic: Corporate: Large companies 1,275 4,607 27,387 33,269 42,349,445 42,382,714 Small and medium-sized 1,386 — 9,185 10,571 3,275,570 3,286,141 Retail: Housing Loan 9,776 7,102 21,257 38,135 7,975,654 8,013,789 Others 5,165 1,123 12,012 18,300 1,872,454 1,890,754 Sovereign — — — — 2,235,890 2,235,890 Banks and other financial institutions — — — — 759,671 759,671 Total domestic 17,602 12,832 69,841 100,275 58,468,684 58,568,959 Foreign: Total foreign — 7,477 30,795 38,272 29,973,636 30,011,908 Total 17,602 20,309 100,636 138,547 88,442,320 88,580,867 2022 Domestic: Corporate: Large companies 323 291 27,275 27,889 42,016,051 42,043,940 Small and medium-sized 693 641 10,370 11,704 3,145,216 3,156,920 Retail: Housing Loan 15,181 8,326 16,548 40,055 7,741,465 7,781,520 Others 4,454 1,068 11,009 16,531 1,690,644 1,707,175 Sovereign — — — — 1,660,345 1,660,345 Banks and other financial institutions — — — — 681,757 681,757 Total domestic 20,651 10,326 65,202 96,179 56,935,478 57,031,657 Foreign: Total foreign — — 28,816 28,816 33,230,110 33,258,926 Total 20,651 10,326 94,018 124,995 90,165,588 90,290,583 Note: The majority of total foreign consist of corporate. Collateral Dependent Loans The MHFG Group uses, as a practical expedient, the fair value of the collateral when recording the net carrying amounts of loans and determining the allowance for credit losses of such loans, for which the repayment is expected to be provided substantially through the operation or sale of the collateral, when the borrower is experiencing financial difficulty based on the assessment as of the reporting date. As of March 31, 2022, collateral relating to these loans was primarily comprised of real estate. There were no significant changes in the extent to which collateral secures these loans during this fiscal year and no significant concentration of collateral against any portfolio segment. Net losses on sales of loans were ¥ 1,036 million, ¥ 8,172 million and ¥3,080 million for the fiscal years ended March 31, 2020, 2021 and 2022, respectively. These net losses include unrealized gains and losses on loans held for sale, representing the adjustments to the lower of cost or fair value at the end of each reporting period. The gains and losses on sales of loans are recorded in Other noninterest income and expenses, respectively.

Allowance for Credit Losses on

Allowance for Credit Losses on Loans	12 Months Ended
	Mar. 31, 2022
Allowance for credit losses on loans	5. Allowance for credit losses on loans Changes in Allowance for credit losses on loans by portfolio segment for the fiscal years ended March 31, 2020, 2021 and 2022 are shown below: Corporate Retail Total (in millions of yen) 2020 Balance at beginning of fiscal year 277,955 29,246 307,201 Provision (credit) for credit losses on loans 149,915 6,285 156,200 Charge-offs (35,021 ) (9,337 ) (44,358 ) Recoveries 26,338 1,578 27,916 Net charge-offs (8,683 ) (7,759 ) (16,442 ) Others (Note) (6,161 ) 57 (6,104 ) Balance at end of fiscal year 413,026 27,829 440,855 2021 Balance at beginning of fiscal year 413,026 27,829 440,855 April 1, 2020 adoption of CECL 77,514 78,241 155,755 Adjusted Balance at beginning of period 490,540 106,070 596,610 Provision (credit) for credit losses on loans 124,086 (11,310 ) 112,776 Charge-offs (72,212 ) (6,589 ) (78,801 ) Recoveries 13,047 888 13,935 Net charge-offs (59,165 ) (5,701 ) (64,866 ) Others (Note) 7,009 (680 ) 6,329 Balance at end of fiscal year 562,470 88,379 650,849 2022 Balance at beginning of fiscal year 562,470 88,379 650,849 Provision (credit) for credit losses on loans 194,022 (6,423 ) 187,599 Charge-offs (55,662 ) (4,178 ) (59,840 ) Recoveries 17,912 842 18,754 Net charge-offs (37,750 ) (3,336 ) (41,086 ) Others (Note) 12,500 (45 ) 12,455 Balance at end of fiscal year 731,242 78,575 809,817 Note: Others includes primarily foreign exchange translation.

Premises and equipment

Premises and equipment	12 Months Ended
	Mar. 31, 2022
Premises and equipment	6. Premises and equipment Premises and equipment at March 31, 2021 and 2022 consist of the following: 2021 2022 (in millions of yen) Land 569,337 571,837 Buildings 737,144 737,440 Equipment and furniture 414,201 373,825 Leasehold improvements 222,296 208,820 Construction in progress 23,441 21,737 Software 1,372,364 1,373,035 Total 3,338,783 3,286,694 Less: Accumulated depreciation and amortization 1,527,325 1,582,627 Premises and equipment—net 1,811,458 1,704,067 Depreciation and amortization expense for premises and equipment for the fiscal years ended March 31, 2020, 2021 and 2022 was ¥234,457 million, ¥223,164 million and ¥220,436 million, respectively. Depreciation and amortization expense related to software was reported in General and administrative expenses, and all other depreciation and amortization expense was reported in Occupancy expenses. The MHFG Group recognized impairment losses of ¥13,490 million on premises and equipment for the fiscal year ended March 31, 2020, of which ¥6,813 million was recorded in General and administrative expenses and ¥6,677 million was recorded in Occupancy expenses. Such losses included ¥6,774 million of impairment losses related mainly to entity-wide software that is for i is is The MHFG Group recognized impairment losses of ¥7,101 million on premises and equipment for the fiscal year ended March 31, 2021, of which ¥3,872 million was recorded in General and administrative expenses and ¥3,229 million was recorded in Occupancy expenses. Such losses included ¥3,397 million of impairment losses related mainly to entity-wide software that is for i is is The MHFG Group recognized impairment losses of ¥13,500 million on premises and equipment for the fiscal year ended March 31, 2022, of which ¥433 million was recorded in General and administrative expenses and ¥13,067 million was recorded in Occupancy expenses. Such losses included ¥12,976 million of impairment losses related mainly to real estate used for the entity-wide assets. Th i is

Goodwill and intangible assets

Goodwill and intangible assets	12 Months Ended
	Mar. 31, 2022
Goodwill and intangible assets	7. Goodwill and intangible assets Goodwill The changes in Goodwill during the fiscal years ended March 31, 2020, 2021 and 2022 are as follows: 2020 2021 2022 (in millions of yen) Balance at beginning of fiscal year 95,151 92,997 92,695 Impairment losses recognized (2,155 ) (302 ) — Foreign exchange translation 1 — — Balance at end of fiscal year 92,997 92,695 92,695 Gross amount of goodwill (Note) 169,313 167,552 161,993 Accumulated impairment losses 76,316 74,857 69,298 Note: Goodwill is recorded at a designated reporting unit level for the purpose of assessing impairment. Goodwill is not allocated to the reportable segments in Note 31 “Business segment information.” Intangible assets The table below presents the gross carrying amount, accumulated amortization and net carrying amount of intangible assets, at March 31, 2021 and 2022: 2021 2022 Gross carrying amount Accumulated amortization Net carrying amount Gross carrying amount Accumulated amortization Net carrying amount (in millions of yen) Intangible assets subject to amortization: Customer relationships (Note) 126,979 79,362 47,617 126,979 87,277 39,702 Other 1,429 1,234 195 1,468 1,237 231 Total 128,408 80,596 47,812 128,447 88,514 39,933 Intangible assets not subject to amortization: Total 8,309 — 8,309 8,006 — 8,006 Total 136,717 80,596 56,121 136,453 88,514 47,939 Note: Customer relationships were acquired in connection with the merger of MHSC and Shinko on May 7, 2009 and the integration among asset management companies on October 1, 2016. See Note 1 “Basis of presentation and summary of significant accounting policies” for further information. For the fiscal years ended March 31, 2020, 2021 and 2022, the MHFG Group recognized ¥9,267 million, ¥8,513 million and ¥7,961 million, respectively, of amortization expense in respect of intangible assets, reported in Other noninterest expenses. The table below presents the estimated aggregate amortization expense in respect of intangible assets for the next five years: (in millions of yen) Fiscal year ending March 31: 2023 7,174 2024 6,660 2025 6,149 2026 5,645 2027 5,138

Pledged assets and collateral

Pledged assets and collateral	12 Months Ended
	Mar. 31, 2022
Pledged assets and collateral	8. Pledged assets and collateral The following amounts, by balance sheet classification, have been pledged as collateral for borrowings and for other purposes at March 31, 2021 and 2022: 2021 2022 (in billions of yen) Interest-bearing deposits in other banks 71 75 Trading account assets 7,424 5,426 Investments 5,573 8,091 Loans 10,417 9,056 Other assets 2,291 3,023 Total 25,776 25,671 The associated liabilities collateralized by the above assets at March 31, 2021 and 2022 are summarized below: 2021 2022 (in billions of yen) Deposits 764 910 Payables under repurchase agreements 6,334 5,864 Payables under securities lending transactions 1,185 645 Other short-term borrowings 6,272 5,113 Long-term debt 192 542 Total 14,747 13,074 The Bank of Japan (“the BOJ”) requires private depository institutions to maintain a certain amount of funds as reserves in current accounts with the BOJ, based on average deposit balances and certain other factors. There are similar reserve deposit requirements for foreign branches and subsidiaries engaged in banking businesses in foreign countries. These amounts are deemed to be restricted cash. At March 31, 2021 and 2022, the deposit amounts maintained with the BOJ and foreign central banks, which were included in Cash and due from banks and Interest-bearing deposits in other banks, were ¥46,346 billion and ¥48,897 billion, respectively. These balances included the reserve funds required to be maintained by the MHFG Group, which amounted to ¥1,617 billion and ¥1,678 billion at March 31, 2021 and 2022, respectively. At March 31, 2021 and 2022, the MHFG Group had received collateral that can be sold or repledged, with a fair value of ¥13,882 billion and ¥16,632 billion, respectively, of which ¥12,583 billion and ¥14,865 billion, respectively, was sold and repledged. Such collateral was primarily obtained in connection with resale or securities borrowing agreements, and was generally used as collateral for repurchase or securities lending agreements, or to cover short sales. This collateral received isn’t recognized on balance sheet.

Deposits

Deposits	12 Months Ended
	Mar. 31, 2022
Deposits	9. Deposits The balance and remaining maturities of time deposits and certificates of deposit issued by domestic and foreign offices at March 31, 2022 are shown in the following table: Time deposits Certificates of deposit Total (in millions of yen) Domestic offices: Due in one year or less 15,082,821 10,224,412 25,307,233 Due after one year through two years 1,374,855 222,560 1,597,415 Due after two years through three years 1,106,825 — 1,106,825 Due after three years through four years 306,455 500 306,955 Due after four years through five years 281,141 — 281,141 Due after five years 188,260 — 188,260 Total 18,340,357 10,447,472 28,787,829 Foreign offices: Due in one year or less 18,439,713 6,065,429 24,505,142 Due after one year through two years 18,847 78,816 97,663 Due after two years through three years 25,388 277,214 302,602 Due after three years through four years 19,581 — 19,581 Due after four years through five years 1,359 — 1,359 Due after five years — — — Total 18,504,888 6,421,459 24,926,347 Total 36,845,245 16,868,931 53,714,176 The aggregate estimated amounts of time deposits and certificates of deposit that meet or exceed insurance limit issued by domestic and foreign offices at March 31, 2021 and 2022 are shown in the following table: 2021 2022 (in billions of yen) Domestic offices: Time deposits 12,004 10,437 Certificates of deposit 10,599 10,448 Total 22,603 20,885 Foreign offices: Time deposits 14,987 18,505 Certificates of deposit 6,594 6,421 Total 21,581 24,926 The aggregate amount of demand deposits in overdraft status that have been reclassified as loan balances at March 31, 2021 and 2022 was ¥627 billion and ¥585 billion, respectively.

Due to trust accounts

Due to trust accounts	12 Months Ended
	Mar. 31, 2022
Due to trust accounts	10. Due to trust accounts MHTB holds assets on behalf of its customers in an agent, fiduciary or trust capacity. Such trust account assets are not the MHFG Group’s proprietary assets and are managed and accounted for separately. However, the cash in individual trust accounts is often placed with MHTB for the customers’ short-term investment needs. These amounts which MHTB owes to the trust accounts are recorded as Due to trust accounts.

Short-term borrowings and long-

Short-term borrowings and long-term debt	12 Months Ended
	Mar. 31, 2022
Short-term borrowings and long-term debt	11. Short-term borrowings and long-term debt Short-term borrowings Short-term borrowings consist of Due to trust accounts, Call money and funds purchased, Payables under repurchase agreements and securities lending transactions, and Other short-term borrowings. Details of Other short-term borrowings at March 31, 2021 and 2022 are as follows: 2021 2022 (in millions of yen) Short-term notes issued by consolidated VIEs of asset-backed commercial paper programs (1) 32,546 46,668 Commercial paper and short-term notes issued by MHFG’s subsidiaries (1) (2) 2,528,568 2,266,360 Borrowings from the Bank of Japan 6,253,123 5,105,225 Other 271,675 148,518 Total 9,085,912 7,566,771 Notes: (1) Short-term notes are issued under the laws of Japan in the form of commercial paper. (2) The amounts of commercial paper and short-term notes issued by MHFG’s subsidiaries were ¥2,105,068 Long-term debt Long-term debt with original maturities of more than one year at March 31, 2021 and 2022 is comprised of the following: 2021 2022 (in millions of yen) Obligations 9,170 4,621 Loan participation borrowings 169,069 220,312 Senior borrowings and bonds 7,494,512 8,600,493 Subordinated borrowings and bonds 4,033,720 3,752,790 Total 11,706,471 12,578,216 The following table presents the interest rates and maturities of senior borrowings and bonds, and subordinated borrowings and bonds: Interest rates (1) Maturities (2) 2021 2022 (%) (in millions of yen) Senior borrowings and bonds: fixed rate denominated in Japanese yen 0.00-6.20 Apr.2022 Jun.2051 547,133 1,032,194 fixed rate denominated in U.S. dollars 0.00-4.55 Apr.2022 Mar.2048 3,275,076 3,581,901 fixed rate denominated in other currencies 0.00-6.00 Apr.2022 May.2041 838,247 1,223,991 floating rate denominated in Japanese yen 0.00-52.70 Apr.2022 Sep.2081 584,606 582,430 floating rate denominated in U.S. dollars 0.00-54.20 Apr.2022 Dec.2061 2,035,844 2,001,616 floating rate denominated in other currencies 0.00-16.70 Apr.2022 Sep.2041 213,606 178,361 Total 7,494,512 8,600,493 Subordinated borrowings and bonds: fixed rate denominated in Japanese yen 0.39-4.26 Jun.2022 3,618,520 3,171,343 fixed rate denominated in U.S. dollars 2.56-4.70 Jul.2022 Sep.2031 415,200 581,447 Total 4,033,720 3,752,790 Total 11,528,232 12,353,283 Notes: (1) The interest rates disclosed reflect the range of contractual rates in effect at March 31, 2022. (2) Maturity information disclosed is the range of maturities at March 31, 2022. (3) None of the long-term debt issuances above are convertible to common stock. (4) Certain debt agreements permit the MHFG Group to redeem the related debt, in whole or in part, prior to maturity at the MHFG Group’s option on terms specified in the respective agreements. The following is a summary of contractual maturities of long-term debt subsequent to March 31, 2022: (in millions of yen) Fiscal year ending March 31: 2023 1,776,915 2024 1,119,756 2025 1,600,277 2026 614,659 2027 1,450,956 2028 and thereafter 6,015,653 Total 12,578,216

Other assets and liabilities

Other assets and liabilities	12 Months Ended
	Mar. 31, 2022
Other assets and liabilities	12. Other assets and liabilities The following table sets forth the details of other assets and liabilities at March 31, 2021 and 2022: 2021 2022 (in millions of yen) Other assets: Accounts receivable: Receivables from brokers, dealers and customers for securities transactions 2,339,902 3,049,874 Other 393,410 557,842 Collateral pledged: Collateral pledged for derivative transactions 1,088,847 1,549,483 Margins provided for futures contracts 297,496 466,531 Other 939,557 1,006,849 Prepaid pension cost 999,962 762,147 Right-of-use 611,533 570,171 Security deposits 104,915 91,766 Loans held for sale 29,834 156,639 Other 651,572 775,940 Total 7,457,028 8,987,242 Other liabilities: Accounts payable: Payables to brokers, dealers and customers for securities transactions 2,576,887 1,406,965 Other 403,501 494,538 Guaranteed trust principal (Note) 814,509 810,776 Lease liabilitie 636,541 593,339 Collateral accepted: Collateral accepted for derivative transactions 763,642 1,075,591 Margins accepted for futures contracts 555,760 327,883 Unearned income 120,521 113,181 Other 1,337,397 1,437,949 Total 7,208,758 6,260,222 Note: Guaranteed trust principal, included in All other liabilities in the disclosure about consolidated VIEs in the accompanying balance sheets, is a liability of certain consolidated trust arrangements that meet the definition of a VIE for which the MHFG Group provides guarantees for the repayment of principal. See Note 24 “Variable interest entities and securitizations” for further discussion of the guaranteed principal money trusts.

Preferred stock

Preferred stock	12 Months Ended
	Mar. 31, 2022
Preferred Stock	13. Preferred stock The composition of preferred stock at March 31, 2020, 2021 and 2022 is as follows: 2020 2021 2022 Class of stock Authorized Issued Authorized Issued Authorized Issued (number of shares) Class XIV preferred stock 90,000,000 — 90,000,000 — 90,000,000 — Class XV preferred stock 90,000,000 — 90,000,000 — 90,000,000 — Class XVI preferred stock 150,000,000 — 150,000,000 — 150,000,000 — Holders or registered pledgees of preferred stock are entitled to receive annual dividends, and distribution of residual assets of MHFG as set out above at the liquidation value per share, prior to holders of common stock but pari passu among themselves. MHFG may pay up to one-half There was no change in balance of the preferred stock in the fiscal years ended March 31, 2020, 2021 and 2022.

Common stock

Common stock	12 Months Ended
	Mar. 31, 2022
Text Block [Abstract]
Common stock	14. Common stock The following table shows the changes in the number of issued shares of common stock during the fiscal years ended March 31, 2020, 2021 and 2022: 2020 2021 2022 (shares) Balance at beginning of fiscal year 2,539,249,894 2,539,249,894 2,539,249,894 Issuance of new shares of common stock due to exercise of stock acquisition rights — — — Balance at end of fiscal year 2,539,249,894 2,539,249,894 2,539,249,894

Dividends

Dividends	12 Months Ended
	Mar. 31, 2022
Text Block [Abstract]
Dividends	15. Dividends The amount available for dividends under Japan’s Companies Act is based on the amount recorded in MHFG’s non-consolidated period-end Pursuant to the Companies Act, in making a distribution of retained earnings, an entity must set aside in its legal reserve an amount equal to one-tenth one-quarter In addition to the provision that requires an appropriation for the legal reserve, the Companies Act and Japan’s Banking Act impose certain limitations on the amount available for dividends. Under the Companies Act, MHFG’s maximum amount available for dividends, at March 31, 2022, was ¥2,147,566 million, based on the amount recorded in MHFG’s general books of account under Japanese GAAP. Under the Banking Act and related regulations, MHFG has to meet the minimum capital adequacy requirements. Distributions of retained earnings, which are otherwise distributable to shareholders, are restricted in order to maintain the minimum capital requirements. See Note 17 “Regulatory matters” for further discussion of regulatory capital requirements. Payment of dividends on shares of common stock is also subject to the prior payment of dividends on shares of preferred stock, if any are outstanding.

Accumulated other comprehensive

Accumulated other comprehensive income (loss), net of tax	12 Months Ended
	Mar. 31, 2022
Accumulated other comprehensive income (loss), net of tax	16. Accumulated other comprehensive income (loss), net of tax Changes in each component of AOCI for the fiscal years ended March 31, 2020, 2021 and 2022 are as follows: 2020 2021 2022 (in millions of yen) AOCI, balance at beginning of fiscal year, previously reported 164,021 (9,494 ) 318,114 Cumulative effect of change in accounting principles (1,052 ) — — AOCI, balance at beginning of fiscal year, adjusted 162,969 (9,494 ) 318,114 Net unrealized gains (losses) on available-for-sale Balance at beginning of fiscal year 22,019 (19,592 ) (8,173 ) Unrealized holding gains (losses) during year (22,566 ) (4,911 ) (35,922 ) Less: reclassification adjustments for losses (gains) included in net income (19,045 ) 16,330 19,049 Change during year (41,611 ) 11,419 (16,873 ) Balance at end of fiscal year (19,592 ) (8,173 ) (25,046 ) Foreign currency translation adjustments: Balance at beginning of fiscal year, previously reported (58,558 ) (109,872 ) (86,873 ) Cumulative effect of change in accounting principles (Note) (1,052 ) — — Balance at beginning of fiscal year, adjusted (59,610 ) (109,872 ) (86,873 ) Foreign currency translation adjustments during year (49,888 ) 22,704 181,722 Less: reclassification adjustments for losses (gains) included in net income (374 ) 295 (745 ) Change during year (50,262 ) 22,999 180,977 Balance at end of fiscal year (109,872 ) (86,873 ) 94,104 Defined benefit plan adjustments: Balance at beginning of fiscal year 196,446 69,455 397,153 Unrealized gains (losses) during year (122,219 ) 331,668 (22,825 ) Less: reclassification adjustments for losses (gains) included in net income (4,772 ) (3,970 ) (18,973 ) Change during year (126,991 ) 327,698 (41,798 ) Balance at end of fiscal year 69,455 397,153 355,355 Own credit risk adjustments : Balance at beginning of fiscal year 4,114 50,515 16,007 Unrealized gains (losses) during year 45,560 (30,345 ) (858 ) Less: reclassification adjustments for losses (gains) included in net income 841 (4,163 ) 550 Change during year 46,401 (34,508 ) (308 ) Balance at end of fiscal year 50,515 16,007 15,699 Total other comprehensive income (loss), net of tax attributable to MHFG shareholders (172,463 ) 327,608 121,998 AOCI, balance at end of fiscal year (9,494 ) 318,114 440,112 Note: The MHFG Group adopted ASU No.2017-12, No.2017-12”) No.2017-12 The following table shows the amounts reclassified out of AOCI into net income during the fiscal year ended March 31, 2022: Before tax (1) Tax effect (2) Net of tax before allocation to noncontrolling interests Net of tax attributable to noncontrolling interests (2) Net of tax attributable to MHFG shareholders (in millions of yen) Amounts reclassified out of AOCI into net income: Affected line items in the consolidated statements of income: Net unrealized gains (losses) on available-for-sale (27,553 ) 8,504 (19,049 ) — (19,049 ) Investment gains (losses)—net Foreign currency translation adjustments 745 — 745 — 745 Investment gains (losses)—net Defined benefit plan adjustments 26,745 (7,748 ) 18,997 (24 ) 18,973 Salaries and employee benefits Own credit risk adjustments (885 ) 271 (614 ) 64 (550 ) Other noninterest income (expenses) Total (948 ) 1,027 79 40 119 Notes: (1) The financial statement line item in which the amounts in the before tax column are reported in the consolidated statements of income is listed to the right of the table. (2) The financial statement line items in which the amounts in the tax effect and the net of tax attributable to noncontrolling interest columns are reported in the consolidated statements of income are Income tax expens e (benefit) and Net income (loss), respectively.

Regulatory matters

Regulatory matters	12 Months Ended
	Mar. 31, 2022
Regulatory matters	17. Regulatory matters Regulatory capital requirements MHFG, MHBK, and MHTB are subject to regulatory capital requirements supervised by the Financial Services Agency in accordance with the provisions of Japan’s Banking Act and related regulations. Certain foreign banking subsidiaries are subject to regulation and control by local supervisory authorities, including central banks. Failure to meet minimum capital requirements may initiate certain mandatory actions by regulators that, if undertaken, could have a direct material effect on the MHFG Group’s consolidated financial condition and results of operations. The capital adequacy guidelines applicable to Japanese banks and bank holding companies with international operations supervised by the Financial Services Agency closely follow the risk-adjusted approach proposed by the Bank for International Settlements and are intended to further strengthen the soundness and stability of Japanese banks. In December 2010, Basel Committee on Banking Supervision (“BCBS”) issued the Basel III rules text, which builds on the International Convergence of Capital Measurement and Capital Standards document (“Basel II”), to strengthen the regulation, supervision and risk management of the banking sector. Basel III rules text presents the details of global regulatory standards on bank capital adequacy and liquidity. The rules text sets out higher and better-quality capital, better risk coverage, introduction of a leverage ratio as a backstop to the risk-based requirement, measures to promote the build-up The Financial Services Agency’s capital adequacy guidelines became effective from March 31, 2013, which generally reflect the rules in the Basel III rules text that have been applied from January 1, 2013. There are three primary regulatory capital ratios used to assess capital adequacy: Common Equity Tier 1, Tier 1 and Total risk-based capital ratios. The ratios are comprised of Common Equity Tier 1 capital, Tier 1 capital (Common Equity Tier 1 capital and Additional Tier 1 capital) and total risk-based capital (Tier 1 and Tier 2 capital) divided by risk-weighted assets. Common Equity Tier 1 capital primarily consists of common stock, capital surplus, retained earnings and AOCI. Regulatory adjustments including certain intangible fixed assets, such as goodwill, and defined-benefit pension fund assets will be deducted from Common Equity Tier 1. Additional Tier 1 capital generally consists of Basel III compliant preferred securities and other capital that meets Tier 1 requirements under Basel II standards, net of regulatory adjustments. Tier 2 capital generally consists of Basel III compliant deferred obligations, such as subordinated debts, capital that meets Tier 2 requirements under Basel II standards, certain allowances for credit losses and noncontrolling interests in subsidiaries’ Tier 2 instruments. Under the revised guidelines, the minimum capital adequacy ratio is 8% on both a consolidated and non-consolidated Under Basel III, capital instruments that no longer qualify as Tier 2 capital were phased out beginning March 2013 by increments of % becoming fully effective in March 2022. The MHFG Group’s existing subordinated debt issued before March 2013 (the amounts thereof included within Tier 2 capital as of March 31, 2021 being ¥168.7 billion) are subject to the phase-out arrangements. As of March 31, 2022 in accordance with Basel III, MHFG Group doesn’t have any more of these instruments included within Tier 2 capital. In November 2015, the Financial Services Agency published the revised capital adequacy guidelines and related ordinances to introduce the capital buffer requirements under the Basel III rules for Japanese banks and bank holding companies with international operations, which include the capital conservation buffer, the countercyclical capital buffer and the additional loss absorbency requirements for global systemically important banks (“G-SIBs”) (“D-SIBs”). G-SIBs D-SIBs build-up G-SIB D-SIB, Leverage ratio The leverage ratio framework is critical and complementary to the risk-based capital framework that will help ensure broad and adequate capture of both on- off-balance Basel III’s leverage ratio is defined as the capital measure (numerator) divided by the exposure measure (denominator) and is expressed as a percentage. The capital measure for the leverage ratio is the Tier 1 capital of the risk-based capital framework, and the exposure measure is the sum of the on-balance off-balance In March 2019, the Financial Services Agency published the revised leverage ratio framework and the minimum leverage ratio is defined as 3% on both a consolidated and non-consolidated In June 2020, in coordination with the monetary policy of the Bank of Japan in response to the impact of COVID-19, COVID-19. The capital requirements and regulatory adjustments are being phased in over a transitional period as follows (italicized percentages indicate those still in transition periods): March 2021 March 2022 March 2023 March 2024 Minimum Common Equity Tier 1 capital 4.5 % 4.5 % 4.5 % 4.5 % Minimum Tier 1 capital 6.0 % 6.0 % 6.0 % 6.0 % Minimum total capital 8.0 % 8.0 % 8.0 % 8.0 % Phase out of recognition of capital instruments that no longer qualify as capital 10.0 % 0.0 % — — Capital conservation buffer 2.5 % 2.5 % 2.5 % 2.5 % Countercyclical capital buffer (1) 0.01 % 0.01 % 0.01 % 0.01 % Additional loss absorbency requirements for G-SIBs D-SIBs (2) 1.0 % 1.0 % 1.0 % 1.0 % Minimum Leverage Ratio 3.0 % 3.0 % 3.5 % (3) 3.5 % (3) Notes: (1) Figures assume that the countercyclical capital buffer will continue to be 0.01% after March 2023. (2) Figures assume that the additional loss absorbency requirements applied to the Group as a G-SIB D-SIB (3) This figure includes a leverage ratio buffer required to be met at 50% of the additional loss absorbency requirements applied to the Group as a G-SIB If the capital adequacy ratio and leverage ratio of a financial institution falls below the required level, the Financial Services Agency may, depending upon the extent of capital deterioration, take certain corrective action, including requiring the financial institution to submit an improvement plan to strengthen its capital base, reduce its total assets, restrict its business operations or other actions that could have a material effect on its financial condition and results of operations. Capital adequacy ratios and leverage ratios of MHFG, MHBK, and MHTB as of March 31, 2021 and 2022 calculated in accordance with Japanese GAAP and the guidelines established by the Financial Services Agency are set forth in the following table: 2021 2022 Amount Ratio Amount Ratio (in billions of yen, except percentages) Consolidated: MHFG: Common Equity Tier 1 capital: Required (1) 5,405 8.01 5,184 8.01 Actual 7,850 11.63 8,067 12.46 Tier 1 capital: Required (1) 6,418 9.51 6,155 9.51 Actual 9,702 14.37 9,713 15.00 Total risk-based capital: Required (1) 7,767 11.51 7,450 11.51 Actual 11,385 16.87 11,351 17.53 Leverage Ratio (2) : Required 6,016 3.00 6,389 3.00 Actual 9,702 4.83 9,713 4.56 MHBK: Common Equity Tier 1 capital: Required 2,823 4.50 2,683 4.50 Actual 6,972 11.11 6,968 11.68 Tier 1 capital: Required 3,764 6.00 3,578 6.00 Actual 8,819 14.05 8,604 14.42 Total risk-based capital: Required 5,019 8.00 4,771 8.00 Actual 10,400 16.57 10,150 17.02 Leverage Ratio (2) : Required 5,660 3.00 5,971 3.00 Actual 8,819 4.67 8,604 4.32 MHTB: Common Equity Tier 1 capital: Required 82 4.50 79 4.50 Actual 527 28.94 442 25.18 Tier 1 capital: Required 109 6.00 105 6.00 Actual 527 28.94 442 25.18 Total risk-based capital: Required 146 8.00 140 8.00 Actual 527 28.94 442 25.18 Leverage Ratio (2) : Required 138 3.00 130 3.00 Actual 527 11.41 442 10.20 Non-consolidated: MHBK: Common Equity Tier 1 capital: Required 2,648 4.50 2,528 4.50 Actual 6,561 11.14 6,293 11.20 Tier 1 capital: Required 3,531 6.00 3,370 6.00 Actual 8,406 14.28 7,919 14.09 Total risk-based capital: Required 4,708 8.00 4,494 8.00 Actual 9,987 16.96 9,483 16.88 Leverage Ratio (2) : Required 5,343 3.00 5,570 3.00 Actual 8,406 4.72 7,919 4.26 2021 2022 Amount Ratio Amount Ratio (in billions of yen, except percentages) MHTB: Common Equity Tier 1 capital: Required 82 4.50 78 4.50 Actual 519 28.63 425 24.40 Tier 1 capital: Required 109 6.00 104 6.00 Actual 519 28.63 425 24.40 Total risk-based capital: Required 145 8.00 139 8.00 Actual 519 28.64 425 24.40 Leverage Ratio (2) : Required 135 3.00 126 3.00 Actual 519 11.51 425 10.09 Notes: (1) The required ratios disclosed above, at March 31, 2021 and 2022, include the capital conservation buffer of 2.5%, the countercyclical capital buffer of 0.01% and the additional loss absorbency requirements for G-SIBs D-SIBs (2) The required and actual amounts disclosed above at March 31, 2021 and March 31, 2022 exclude amounts of deposits to the Bank of Japan. MHFG’s securities subsidiary in Japan is also subject to the capital adequacy requirement under Japan’s Financial Instruments and Exchange Act. Under this requirement, securities firms must maintain a minimum capital adequacy ratio of 120% calculated as a percentage of capital accounts less certain assets, as calculated using Japanese GAAP figures, against amounts equivalent to market, counterparty, and basic risks. Specific guidelines are issued as a ministerial ordinance that details the definition of essential components of the capital ratios, including capital, disallowed assets and risks, and related measures. Failure to maintain a minimum capital ratio will trigger mandatory regulatory actions. A capital ratio of less than 140% will call for regulatory reporting and a capital ratio of less than 100% may lead to a temporary suspension of all or part of the business operations and further, to the cancellation of the license to act as a securities broker and dealer. Management believes, as of each latest balance sheet date, that MHFG, MHBK, MHTB, and their securities subsidiary in Japan and foreign banking subsidiaries were in compliance with all capital adequacy requirements to which they were subject. Business improvement orders MHFG and MHBK received business improvement orders dated November 26, 2021 from the Financial Services Agency of Japan pursuant to Clause 1 of Article 52-33 and Clause 1 of Article 26 of the Banking Act of Japan, in regard to the series of IT system failures that have occurred from February to September 2021. In response to this, MHFG and MHBK submitted the business improvement plans to the Financial Services Agency of Japan. MHFG and MHBK have been implementing measures to prevent further incidents based on the business improvement plans and building up crisis response capability in a multidimensional manner. See Note 23 “Commitments and contingencies” for further information on the impact that these orders have on the consolidated financial statements.

Earnings per common share

Earnings per common share	12 Months Ended
	Mar. 31, 2022
Earnings per common share	18. Earnings per common share The following table sets forth the computation of basic and diluted earnings per common share for the fiscal years ended March 31, 2020, 2021 and 2022: 2020 2021 2022 (in millions of yen) Net income (loss): Net income (loss) attributable to MHFG common shareholders 150,195 581,765 (104,722 ) Effect of dilutive securities — — — Net income (loss) attributable to common shareholders after assumed conversions 150,195 581,765 (104,722 ) 2020 2021 2022 (thousands of shares) Shares: Weighted average common shares outstanding 2,537,368 2,537,513 2,537,051 Effect of dilutive securities: Stock options and the common shares of MHFG under the stock compensation programs (Note) 158 89 — Weighted average common shares after assumed conversions 2,537,526 2,537,602 2,537,051 2020 2021 2022 (in yen) Earnings per common share: Basic net income (loss) per common share 59.19 229.27 (41.28 ) Diluted net income (loss) per common share (Note) 59.19 229.26 (41.28 ) Note: For the fiscal years ended March 31, 2020, 2021 and 2022, the performance-based plan under the stock compensation programs could potentially dilute earnings per common share but were not included in the computation of diluted earnings per common share due to their antidilutive effects. In addition, for the fiscal year ended March 31, 2022, the computation of diluted earnings per common share did not assume exercise of stock options, as the effect of such exercise would be antidilutive

Income taxes

Income taxes	12 Months Ended
	Mar. 31, 2022
Income taxes	19. Income taxes Income tax expense (benefit) The following table presents the components of Income tax expense (benefit) for the fiscal years ended March 31, 2020, 2021 and 2022: 2020 2021 2022 (in millions of yen) Current: Domestic 96,231 81,023 42,401 Foreign 52,885 78,992 71,947 Total current tax expense 149,116 160,015 114,348 Deferred: Domestic (111,341 ) 55,927 (256,093 ) Foreign 9,400 (5,226 ) 728 Total deferred tax expense (benefit) (101,941 ) 50,701 (255,365 ) Total income tax expense (benefit) 47,175 210,716 (141,017 ) The preceding table does not reflect the tax effects of items recorded directly in Equity for the fiscal years ended March 31, 2020, 2021 and 2022. The detailed amounts recorded directly in Equity are as follows: 2020 2021 2022 (in millions of yen) Net unrealized gains (losses) on available-for-sale Unrealized gains (losses) (10,012 ) (2,810 ) (16,489 ) Less: reclassification adjustments (8,410 ) 7,195 8,504 Total (18,422 ) 4,385 (7,985 ) Defined benefit plan adjustments: Unrealized gains (losses) (52,888 ) 143,653 (9,020 ) Less: reclassification adjustments (1,765 ) (1,424 ) (7,748 ) Total (54,653 ) 142,229 (16,768 ) Own credit risk adjustments: Unrealized gains (losses) 5,052 919 1,745 Less: reclassification adjustments 387 (1,911 ) 271 Total 5,439 (992 ) 2,016 Total tax effect before allocation to noncontrolling interests (67,636 ) 145,622 (22,737 ) Reconciliation of Income tax expense (benefit) The following table shows a reconciliation of Income tax expense at the effective statutory tax rate to the actual income tax expense for the fiscal years ended March 31, 2020, 2021 and 2022: 2020 2021 2022 (in millions of yen, except tax rates) Income (loss) (benefit) 153,490 1,028,764 (242,488 ) Effective statutory tax rate 30.62 % 30.62 % 30.62 % Income tax calculated at the statutory tax rate 46,999 315,007 (74,250 ) Income not subject to tax (7,758 ) (7,446 ) (10,219 ) Expenses not deductible for tax purposes 1,290 728 828 Tax rate differentials of subsidiaries (5,756 ) (9,252 ) (8,035 ) Change in valuation allowance 5,984 (39,410 ) 16,196 (Note) Noncontrolling interest income (loss) of consolidated VIEs 14,796 (70,143 ) 5,088 Effect of enacted change in tax rates (210 ) (213 ) (29 ) Reversal of outside basis differences — — (122,633 ) (Note) Foreign tax credit and payments 1,823 1,657 40,228 Income excluded from taxable income of enterprise ta x (4,040 ) (5,076 ) (6,944 ) Oth e r (5,953 ) 24,864 18,753 Income tax expense (benefi t ) 47,175 210,716 (141,017 ) Note: These amounts for the fiscal year ended March 31, 2022 mainly represent the reversal of an outside basis difference related to the share buyback conducted by MHSC in response to improving the capital position and aligning to the MHFG Group’s capital policy and the related increase in the valuation allowance. Deferred tax assets and liabilities The components of n e 2021 2022 (in millions of yen) Deferred tax assets: Allowance for credit losses 247,983 292,277 Lease liabilities 195,629 183,537 Trading securities 8,519 118,242 Premises and equipment 64,389 65,051 Derivative financial instruments 14,893 52,321 Available-for-sale 1,164 8,313 Net operating loss carryforwards (1) 151,383 183,410 (2) Other 237,730 223,564 921,690 1,126,715 Valuation allowance (1) (129,150 ) (163,164 ) (2) Deferred tax assets, net of valuation allowance 792,540 963,551 Deferred tax liabilities: Prepaid pension cost and accrued pension liabilities 292,397 221,256 Investments 259,276 213,398 Right-of-use 188,902 176,591 Other 83,952 104,020 Deferred tax liabilities 824,527 715,265 Net deferred tax assets (liabilities) (31,987 ) 248,286 Notes: (1) The amount includes ¥85,001 million and ¥73,736 million related to MHSC’s net operating loss carryforwards resulting mainly from the organizational restructuring of certain foreign subsidiaries as of March 31, 20 2 (2) The amount includes ¥26,633 million related to MHFG’s net operating loss carryforwards resulting mainly from intercompany capital transactions in relation to the share buyback conducted by MHSC as of March 31, 2022. The tax effect of the net operating loss carryforwards is substantially offset by ¥24,675 million of valuation allowance as a result of considering all available evidence regarding sources of future taxable income including historical trends in taxable income in the preceding periods and forecasted taxable income. Deferred tax assets and deferred tax liabilities within the same tax jurisdiction have been netted for presentation purposes in the consolidated balance sheets. As of March 31, 2022, the accumulated amount of undistributed earnings that will be indefinitely reinvested and the unrecognized deferred tax liabilities related to such subsidiaries are approximately ¥285 billion and ¥30 billion, respectively. The following table and accompanying footnotes provide a breakdown of deferred tax assets and the valuation allowance recognized in respect of net operating loss carryforwards by tax jurisdiction and by year of expiration as of March 31, 2021 and 2022: Deferred tax assets Valuation allowance Deferred tax assets, net of valuation allowance (in billions of yen) 2021 Japan (1) 94 (64 ) 30 The United States 2 — 2 The United Kingdom (2) 54 (54 ) — Others 1 — 1 Total 151 (118 ) 33 2022 Japan (3) 106 (77 ) 29 The United States 1 — 1 The United Kingdom (2) 75 (75 ) — Others 1 — 1 Total 183 (152 ) 31 Notes: (1) ¥85 billion of the Japan deferred tax assets of ¥94 billion is related to MHSC, which is substantially offset by a valuation allowance, and will expire during the fiscal year ending March 31, 2026. (2) The United Kingdom net operating loss carryforwards may be carried forward indefinitely for tax purposes. (3) ¥74 billion of the Japan deferred tax assets of ¥106 billion is related to MHSC, which is substantially offset by a valuation allowance, and will expire during the fiscal year ending March 31, 2026. ¥27 billion of the Japan deferred tax assets of ¥106 billion is related to MHFG, which is substantially offset by a valuation allowance, and will mostly Determination of valuation allowance In accordance with ASC 740, when the MHFG Group determines whether and to what extent a valuation allowance is needed, the Group considers all available evidence, both positive and negative, to estimate future taxable income. In this regard, the Group considers reversals of existing taxable temporary differences, projected future taxable income (exclusive of reversals of existing temporary differences) and qualifying tax-planning available-for-sale tax-planning available-for-sale Positive evidence includes the Group’s results of operations for the current and preceding years on an overall consolidated basis and for most of the principal subsidiaries. In particular, the strong results of operations in recent years of MHFG’s principal banking subsidiaries in Japan represent positive evidence that can be objectively verified. Negative evidence includes the existence of significant amounts of net operating loss carryforwards or cumulative losses recorded at certain entities, and the expiration of unused net operating loss carryforwards in recent years. A valuation allowance is recorded against deferred tax assets as of the balance sheet date to the extent the Group estimates it is more likely than not that sufficient future taxable income is not available to realize such deferred tax assets. As the Group did not apply a consolidated taxation system for the fiscal years ended March 31, 2020 and 2021, with a few exceptions of certain subsidiaries, deferred tax assets and liabilities are calculated separately for each legal entity. The Group has appl i In general, a valuation allowance is recognized against deferred tax assets related to entities that have accumulated significant net operating loss carryforwards. As of March 31, 2022, the Group’s valuation allowance was primarily related to entities in Japan, the United States and the United Kingdom. The valuation allowance was partially recognized in Japan and in the United States, while the valuation allowance was fully recognized in the United Kingdom. The Group determined whether cumulative losses were recognized by aggregating pretax results for the recent three years as part of the analysis of potential indicators of negative evidence. In each tax jurisdiction, certain entities recognized a cumulative loss on the basis of the most recent three years’ pretax results as of March 31, 2022. A valuation allowance was fully recognized against the deferred tax assets if the Group determined there was no positive evidence that overcame the negative evidence. As of March 31, 2022, MHFG’s securities subsidiary in the United Kingdom recorded cumulative losses on the basis of the recent three years’ pretax results and recognized a full valuation allowance, as there was no positive evidence to overcome the negative evidence. MHFG and its principal banking subsidiaries in Japan did not record cumulative losses in the periods presented. Change in valuation allowance The following table presents a roll-forward of the valuation allowance for the fiscal years ended March 31, 2020, 2021 and 2022: 2020 2021 2022 (in millions of yen) Balance at beginning of fiscal year 158,581 165,278 129,150 Changes that directly affected Income tax expense 5,984 (39,410 ) 16,196 Changes that did not affect Income tax expense: Expiration of net operating loss carryforwards — — — Others 713 3,282 17,818 Tota l 713 3,282 17,818 Balance at end of fiscal year 165,278 129,150 163,164 The increase in the fiscal year ended March 31, 2020 of ¥5,984 million in the valuation allowance that directly affected Income tax expense was primarily related to a decrease of the realizability of deferred tax assets of MHFG and its subsidiaries. The decrease in the fiscal year ended March 31, 2021 of ¥39,410 million in the valuation allowance that directly affected Income tax expense was primarily related to an increase of the realizability of deferred tax assets of MHFG and its subsidiaries. The increase in the fiscal year ended March 31, 2022 of ¥16,196 million in the valuation allowance that directly affected Income tax expense was primarily related to a decrease of the realizability of deferred tax assets of MHFG and its subsidiaries. The increase in the fiscal year ended March 31, 2022 of ¥17,818 million in others was primarily related to an incre a subsidiary. Net operating loss carryforwards At March 31, 2022, the MHFG Group had net operating loss carryforwards totaling ¥589 billion. These carryforwards are scheduled to expire as follows: Net operating loss carryforwards (1) (in billions of yen) Fiscal year ending March 31: 2023 — 2024 — 2025 — 2026 246 2027 3 2028 and thereafter (2) 340 Total 589 Notes: (1) Net operating loss carryforwards related to Japanese local taxes recorded at MHFG in the fiscal year ended March 31, 2022 in the amount of ¥499 billion (tax effected ¥24 billion) are not included in the table. The net operating loss carryforwards is fully offset by valuation allowance and will expire during the fiscal year ending March 31, 2032. (2) Including the net operating loss carryforwards which may be carried forward indefinitely in the United Kingdom. In addition, included in the net operating loss carryforwards in the above table are MHSC’s net operating loss carryforwards of ¥246 billion resulting mainly from the reversal of an outside basis difference related to certain foreign subsidiaries due to their organizational restructuring. The tax loss was recorded at MHSC in accordance with Japanese tax law. The net operating loss carryforwards due to this restructuring will expire during the fiscal year ending March 31, 2026. Uncertainty in income tax The following table is a roll-forward of unrecognized tax benefits for the fiscal years ended March 31, 2020, 2021 and 2022: 2020 2021 2022 (in millions of yen) Total unrecognized tax benefits at beginning of fiscal year 12,323 3,374 4,401 Gross amount of increases (decreases) related to positions taken during prior years 199 455 (576 ) Gross amount of increases related to positions taken during the current year 328 524 954 Amount of decreases related to settlements (9,420 ) — — Foreign exchange translation (56 ) 48 466 Total unrecognized tax benefits at end of fiscal year 3,374 4,401 5,245 The total amount of unrecognized tax benefits including ¥1,477 million, ¥1,463 million and ¥1,812 million of interest and penalties was ¥3,374 million, ¥4,401 million and ¥5,245 million at March 31, 2020, 2021 and 2022, respectively, which would, if recognized, affect the Group’s effective tax rate. The Group classifies interest and penalties accrued relating to unrecognized tax benefits as Income tax expense. The MHFG Group is currently subject to ongoing tax audits in some jurisdictions. The oldest years open to tax audits in Japan, the United States and the United Kingdom are 2013, 2002 and 2018, respectively. The Group does not anticipate that increases or decreases of unrecognized tax benefits within the next twelve months would have a material effect on its consolidated results of operations or financial condition.

Pension and other employee bene

Pension and other employee benefit plans	12 Months Ended
	Mar. 31, 2022
Pension and other employee benefit plans	20. Pension and other employee benefit plans Severance indemnities and pension plans MHFG and certain subsidiaries sponsor and offer their employees, other than directors and corporate auditors, contributory and non-contributory lump-sum lump-sum Certain foreign offices and subsidiaries have defined contribution plans and/or defined benefit plans, of which disclosures are combined with those for domestic benefit plans, as they are not significant and those plans don’t use significantly different assumptions. MHFG and certain subsidiaries have several defined contribution plans. The costs recognized in respect of contributions to the plans for the fiscal years ended March 31, 2020, 2021 and 2022 were ¥3,142 million, ¥4,510 million and ¥3,981 million, respectively. Pension plans are not fully integrated among subsidiaries of MHFG and plan assets are managed separately by each plan. Net periodic benefit cost and funded status The following table presents the components of net periodic cost of the severance indemnities and pension plans for the fiscal years ended March 31, 2020, 2021 and 2022: 2020 2021 2022 (in millions of yen) Service cost-benefits earned during the fiscal year 45,697 39,672 33,190 Interest costs on projected benefit obligations 5,590 5,790 5,636 Expected return on plan assets (40,551 ) (41,887 ) (37,051 ) Amortization of prior service cost (benefits) 121 (2,378 ) (4,820 ) Amortization of net actuarial loss (gain) (5,873 ) 1,671 (20,485 ) Special termination benefits 9,793 9,569 10,791 Loss (gain) on settlement — (3,945 ) — Net periodic benefit cost 14,777 8,492 (12,739 ) Other changes in plan assets and benefit obligations recognized in other comprehensive income (loss) before-tax 2021 2022 (in millions of yen) Net actuarial gain (loss) 395,028 (36,796 ) Amortization of net actuarial loss (gain) 1,671 (20,485 ) Settlement loss (gain) of net actuarial loss (gain) (3,945 ) — Prior service benefits (cost) 74,160 (1 ) Amortization of prior service cost (benefits) (2,378 ) (4,820 ) Total recognized in other comprehensive income (loss) before-tax 464,536 (62,102 ) Weighted-average assumptions used to determine benefit obligations and net periodic benefit cost are as follows: 2020 2021 2022 Weighted-average assumptions used to determine benefit obligations at fiscal year end: Discount rates 0.37 % 0.38 % 0.52 % Rates of increase in future compensation levels 1.80-4.80 % 1.80 % 2.00 % Interest credit rates 4.95 % 4.38 % 4.39 % Weighted-average assumptions used to determine net periodic benefit cost during the Discount rates 0.34 % 0.37 % 0.38 % Rates of increase in future compensation levels 1.80-4.80 % 1.80-4.80 % 1.80 % Expected rates of return on plan assets 1.68 % 1.79 % 1.54 % Interest credit rates 4.97 % 4.95 % 4.38 % In estimating the discount rates, the MHFG Group looks to interest rates on a portfolio of high-quality fixed-income government and corporate bonds. The durations of these bonds closely match those of the benefit obligations. Discount rates are evaluated at each measurement date. The expected rate of return for each asset category is based primarily on various aspects of the long-term prospects for the economy that include historical performance and the market environment. The following table sets forth the combined funded status and amounts recognized in the accompanying consolidated balance sheets at March 31, 2021 and 2022 for the plans of MHFG and its subsidiaries: 2021 2022 (in millions of yen) Change in benefit obligations: Benefit obligations at beginning of fiscal year 1,571,296 1,437,843 Service cost 39,672 33,190 Interest cost 5,790 5,636 Plan participants’ contributions 1,131 1,089 Amendments (1) (74,160 ) 1 Actuarial loss (gain) (6,938 ) (19,939 ) Foreign exchange translation 2,971 4,099 Benefits paid (52,930 ) (54,483 ) Lump-sum (27,357 ) (29,697 ) Settlement (2) (21,632 ) — Benefit obligations at end of fiscal year 1,437,843 1,377,739 Change in plan assets: Fair value of plan assets at beginning of fiscal year 2,252,624 2,412,745 Actual return (negative return) on plan assets 395,555 (8,008 ) Foreign exchange translation 3,570 3,863 Partial withdrawal of assets from employee retirement benefits trusts (3) (188,299 ) (270,172 ) Employer contributions 24,939 28,977 Plan participants’ contributions 1,131 1,089 Benefits paid (52,930 ) (54,483 ) Settlement (2) (23,845 ) — Fair value of plan assets at end of fiscal year 2,412,745 2,114,011 Funded status 974,902 736,272 Amounts recognized in the consolidated balance sheets consist of: Prepaid pension cost 999,962 762,147 Accrued pension liability (25,060 ) (25,875 ) Net amount recognized 974,902 736,272 Amounts recognized in Accumulated other comprehensive income (loss) before-tax Prior service benefits (cost) 67,856 63,030 Net actuarial gain (loss) 478,966 421,690 Net amount recognized 546,822 484,720 Notes: (1) The amount of ¥74,160 million for March 31, 2021 includes ¥73,998 million of prior service benefits recognized during the six months ended September 30, 2020 related to an amendment to the defined benefit pension plans at MHFG and certain domestic subsidiaries. In September 2020, based on various approvals, MHFG and certain domestic subsidiaries communicated to their employees the amendment to the defined benefit pension plans that was effective as of October 1, 2020. In accordance with ASC 715, “Compensation—Retirement Benefits” (“ASC 715”), any change in projected benefit obligations due to a plan amendment is required to be recognized as prior service benefits (cost) as of the amendment date. (2) The amount of ¥21,632 million and ¥23,845 million of settlement for March 31, 2021 resulted from partial transition from the defined benefit pension plans to the defined contribution pension plans, which occurred during the second half of the fiscal year ended March 31, 2021 at MHFG and certain domestic subsidiaries. This partial transition constitutes a settlement under ASC 715 and any gain or loss is required to be recognized in the consolidated results of operations once settlement criteria are met. The settlement criteria were met during the second half of the fiscal year ended March 31, 2021. (3) During the fiscal year ended March 31, 2021 and 2022, certain subsidiaries of MHFG partially withdrew assets from employee retirement benefit trusts, which were established for the payment of employees’ severance pay and retirement pensions. Overall, the trusts remain in overfunded status as of March 31, 2022. No gains or losses have been recognized as a result of this transaction. The aggregated accumulated benefit obligations of these plans were ¥1,437,843 million and ¥1,377,739 million, as of March 31, 2021 and 2022, respectively. The defined benefit plans generally employ a multi-variable and non-linear lump-sum The following table shows the projected benefit obligations and the fair value of plan assets for the plans of MHFG and its subsidiaries with projected benefit obligations in excess of plan assets, and the accumulated benefit obligations and the fair value of plan assets for the plans with accumulated benefit obligations in excess of plan assets at March 31, 2021 and 2022: 2021 2022 (in millions of yen) Plans with projected benefit obligations in excess of plan assets: Projected benefit obligations 49,110 31,829 Fair value of plan assets 24,050 5,954 Plans with accumulated benefit obligations in excess of plan assets: Accumulated benefit obligations 49,110 31,829 Fair value of plan assets 24,050 5,954 Note: The plans with projected benefit obligations in excess of plan assets include those with accumulated benefit obligations in excess of plan assets. Investment policies and asset allocation In managing plan assets, the MHFG Group determines the appropriate levels of risk that the Group can assume under the given circumstances to maximize the investment returns from a long-term perspective while ensuring that sufficient funds will be available to plan participants and beneficiaries. Generally, the investment returns are relative to the risks involved. In considering the maximum levels of risk that the MHFG Group can assume, it primarily considers the following factors: the employers’ burden of maintaining the benefit plans based on the design of the plans and future plan contributions, the age distribution of the plan participants and beneficiaries, the financial conditions of the employers, and the employers’ ability to absorb future variability in plan premiums. The long-term asset allocation to each asset category such as Japanese equity securities, Japanese debt securities, foreign equity securities and foreign debt securities is determined based upon the optimal portfolio, which is estimated to yield the maximum return within the range of an acceptable level of risk. Additionally, the asset allocation is reviewed whenever there are large fluctuations in pension plan liabilities caused by modifications of pension plans, or there are changes in the market environment. When selecting an investment in each asset category, the MHFG Group takes into consideration credit standing of an investee, concentration of credit risk to a certain investee and liquidity of a financial instrument among other things. The investments in each asset category are further diversified across funds, strategies and sectors along with other things. There is no significant investment in a single investee except Japanese government bonds. Certain subsidiaries of MHFG established employee retirement benefit trusts and transferred their assets to the trusts as plan assets. These assets are separated from the employer’s proprietary assets for the payment to the plan beneficiaries. The assets held in these trusts are primarily Japanese equity securities and have been entrusted directly to qualified trustees including trust banks. MHFG and certain subsidiaries’ target allocation for the plan assets, excluding those of the employee retirement benefit trusts, at March 31, 2022 is as follows: Asset category Asset ratio Japanese equity securities 5.00 % Japanese debt securities 34.00 % Foreign equity securities 25.00 % Foreign debt securities 23.00 % General account of life insurance companies 11.00 % Other 2.00 % Total 100.00 % Note: General account of life insurance companies is a contract with life insurance companies which guarantees payments of principal and predetermined interest payments. Fair value of plan assets The following table presents the fair value of plan assets of MHFG and its subsidiaries at March 31, 2021 and 2022, by asset class. For the detailed information on fair value measurements, including descriptions of Level 1, 2 and 3 of the fair value hierarchy and the valuation methodologies, see Note 27 “Fair value.” 2021 2022 Level 1 Level 2 Level 3 Total Level 1 Level 2 Level 3 Total (in billions of yen) Japanese equity securities: Common stocks (1) 1,291 — — 1,291 1,003 — — 1,003 Pooled funds (2) 13 5 — 18 13 5 — 18 Japanese debt securities: Government bonds 188 — — 188 179 — — 179 Pooled funds (2) — 9 — 9 — 10 — 10 Other — 23 — 23 — 21 — 21 Foreign equity securities: Common stocks 157 — — 157 172 — — 172 Pooled funds (2) — 6 — 6 — 7 — 7 Foreign debt securities: Government bonds 180 7 — 187 170 9 — 179 Pooled funds (2) — 12 — 12 — 10 — 10 Other — 19 — 19 — 18 — 18 General account of life insurance companies (3) — 115 — 115 — 116 — 116 Other 30 (4) (13 ) — 17 30 (4) (25 ) — 5 Plan assets measured at net asset value (5) 371 376 Total assets at fair value 1,859 183 — 2,413 1,567 171 — 2,114 Notes: (1) This class represents equity securities held in the employee retirement benefit trusts of ¥1,291 billion and ¥1,003 billion carried at fair value at March 31, 2021 and 2022, respectively, which are well-diversified across industries. (2) These classes primarily include pension investment fund trusts. Investments in these classes are generally measured at fair value and can be redeemed within a short-term period upon request. (3) Investments in this class are measured at conversion value, which is equivalent to fair value. (4) Amounts primarily include cash and short-term assets carried at fair value. (5) In accordance with ASC 820, certain plan assets that are measured at fair value using the net asset value per share (or its equivalent) practical expedient have not been classified in the fair value hierarchy. There were no returns on and purchases and sales of Level 3 assets during the fiscal years ended March 31, 2021 and 2022. Contributions The total contribution of approximately ¥29 billion is expected to be paid to the pension plans during the fiscal year ending March 31, 2023, based on the current funded status and expected asset return assumptions. Estimated future benefit payments The following table presents forecasted benefit payments including the effect of expected future service for the fiscal years indicated: (in millions of yen) Fiscal year ending March 31: 2023 76,933 2024 76,956 2025 76,662 2026 77,281 2027 75,557 2028-2032 344,156

Stock-based compensation

Stock-based compensation	12 Months Ended
	Mar. 31, 2022
Share-based Payment Arrangement [Abstract]
Stock-based compensation	21. Stock-based compensation Stock options MHFG, MHBK, MHTB and MHSC have stock options, in the form of stock acquisition rights, for directors (excluding the outside directors) and executive officers of the respective companies (hereinafter referred to collectively as the “Directors”). In this plan (“MHFG Stock Plan”), 100 shares of MHFG common stock shall be issued or transferred upon exercise of each of the stock acquisition rights. The exercise price is 1 yen per share. The contractual term of the stock acquisition rights is 20 years. A holder may exercise the stock acquisition rights only after the date on which such holder loses the status as a Director of MHFG, MHBK, MHTB or MHSC. The following is a roll-forward of MHFG Stock Plan for the fiscal year ended March 31, 2022: Number of shares Weighted-average exercise price Weighted-average remaining contractual term Aggregate intrinsic value (in yen) (in years) (in millions of yen) Outstanding at beginning of fiscal year 85,700 1 Exercised during fiscal year 24,200 1 Outstanding at end of fiscal year 61,500 1 11.58 96 Exercisable at end of fiscal year — — — — There were no non-vested In May 2015, MHFG discontinued the stock option program. Thereafter, MHFG has not issued any new stock options. Stock compensation programs MHFG, MHBK, MHTB and MHSC introduced a responsibility-based stock compensation program for Directors (“Stock Compensation I”) in July 2018 and a performance-based stock compensation program for Directors (“Stock Compensation II”) in May 2015. MHFG and certain consolidated subsidiaries introduced both responsibility-based and performance-based stock compensation program for Operating Officers (“Stock Benefit”) in July 2021. The stock compensation is paid in the form of shares of common stock of MHFG, acquired from the stock market through a trust, with the aim of aligning the Directors’ and Operating Officers’ interests with those of the shareholders and increasing the incentive to enhance corporate value. Stock Compensation I, in principle, is paid at the time of retirement of the individual Directors in the form of common stock of MHFG and cash, calculated based on their responsibilities. Stock Compensation II is calculated and then paid to the Directors based on MHFG Group’s immediate, prior-period performance, the recent performance of organizations that the Directors are in charge of, and the performance of each Director. The payment in the form of common stock of MHFG and cash is deferred over a three-year, graded-vesting period. Stock Benefit is calculated and then paid to the Operating Officers based on their responsibilities in their respective company and MHFG Group’s performance. The payment in the form of common stock of MHFG and cash is deferred over a one-year In relation to Stock Benefit, which has been introduced in July 2021, there was no responsibility-based and performance-based stock compensation that granted or vested or compensation cost recognized for the fiscal year ended March 31, 2022. The following table presents activities related to the stock compensation programs for the fiscal years ended March 31, 2021 and 2022: Stock Compensation I Stock Compensation II 2021 Number of shares Weighted-average grant-date fair value Number of shares Weighted-average grant-date fair value (per share in yen) (per share in yen) Nonvested at the beginning of the year — — 1,142,329 1,775.08 Granted during fiscal year 365,074 1,390.08 730,726 1,390.08 Vested during fiscal year 365,074 1,390.08 245,266 1,665.35 Forfeited during fiscal year — — — — Nonvested at the end of the year — — 1,627,789 1,618.79 Stock Compensation I Stock Compensation II 2022 Number of shares Weighted-average grant-date fair value Number of shares Weighted-average grant-date fair value (per share in yen) (per share in yen) Nonvested at the beginning of the year — — 1,627,789 1,618.79 Granted during fiscal year 329,839 1,570.97 732,161 1,570.97 Vested during fiscal year 329,839 1,570.97 293,856 1,614.11 Forfeited during fiscal year — — — — Nonvested at the end of the year — — 2,066,094 1,602.51 The following table presents the total fair value of the stock compensation that vested and the total amount of the common stock acquired from the stock market by the trustee for the fiscal years ended March 31, 2021 and 2022: 2021 2022 Stock Compensation I Stock Compensation II Stock Compensation I Stock Compensation II (in millions of yen) Fair value of vested shares 507 221 518 463 Common stock shares acquired 507 1,016 518 1,150 For both programs, the stock-based compensation cost is determined based on the fair value of MHFG’s common stock as of grant date. For Stock Compensation I and II, the liability related to the cash-based compensation cost is remeasured at each reporting date based on the fair value of MHFG’s common stock. For Stock Compensation II, the stock-based compensation costs are recognized evenly over the graded-vesting period, which is three years. For Stock Compensation I, as the program is effectively vested on the grant date, the stock-based compensation cost is recognized on the grant date. The following table presents the compensation cost recognized in the stock compensation programs for the fiscal years ended March 31, 2020, 2021 and 2022: 2020 2021 2022 (in millions of yen) Stock Compensation I 917 507 518 Stock Compensation II 1,247 1,053 1,013 With regard to Stock Compensation II, the total compensation cost related to non-vested

Derivative financial instrument

Derivative financial instruments	12 Months Ended
	Mar. 31, 2022
Derivative financial instruments	22. Derivative financial instruments The MHFG Group enters into derivative financial instruments in response to the diverse needs of customers, to manage the risk related to the assets and liabilities of the Group, as part of its asset and liability management, and for proprietary trading purposes. The Group is exposed primarily to market risk associated with interest rate, commodity, foreign currency, and equity products. Market risk arises from changes in market prices or indices, interest rates and foreign exchange rates that may result in an adverse change in the market value of the financial instrument or an increase in its funding costs. Exposure to market risk is managed by imposing position limits and monitoring procedures and by initiating hedging transactions. In addition to market risk, the Group is exposed to credit risk associated with counterparty default or nonperformance in respect of transactions. Counterparty credit risk arises when a counterparty fails to perform according to the terms and conditions of the contract and the value of the underlying collateral held, if applicable, is not sufficient to recover resulting losses. The exposure to counterparty credit risk is measured by the fair value of all derivatives and its potential exposure at the balance sheet dates. The exposure to counterparty credit risk is managed by entering into legally enforceable master netting agreements to mitigate the overall counterparty credit risk, requiring underlying collateral and guarantees based on an individual credit analysis of each obligor and evaluating the credit features of each instrument. In addition, credit approvals, limits and monitoring procedures are also imposed. Notional and fair value amounts of derivative instruments The following table summarizes the notional and fair value amounts of derivative instruments outstanding as of March 31, 2021 and 2022. The fair values of derivatives are presented on a gross basis; derivative receivables and payables are not offset. In addition, they are not offset against the amounts recognized for the right to reclaim cash collateral or the obligation to return cash collateral under master netting agreements in the consolidated balance sheets, or the table below. Fair value Derivative receivables (2) Derivative payables (2) 2021 Notional amount (1) Designated as hedges Not designated as hedges Designated as hedges Not designated as hedges (in billions of yen) Interest rate contracts 1,174,835 — 4,639 — 4,476 Foreign exchange contracts 182,809 — 3,328 — 3,246 Equity-related contracts 7,865 — 531 — 384 Credit-related contracts 10,431 — 94 — 113 Other contracts 413 — 33 — 33 Total 1,376,353 — 8,625 — 8,252 Fair value Derivative receivables (2) Derivative payables (2) 2022 Notional amount (1) Designated as hedges Not designated as hedges Designated as hedges Not designated as hedges (in billions of yen) Interest rate contracts 1,395,950 — 4,624 — 4,716 Foreign exchange contracts 217,462 — 4,436 — 4,472 Equity-related contracts 9,887 — 426 — 345 Credit-related contracts 11,857 — 118 — 121 Other contracts 681 — 119 — 116 Total 1,635,837 — 9,723 — 9,770 Notes: (1) Notional amount includes the sum of gross long and gross short third-party contracts. (2) Derivative receivables and payables are recorded in Trading account assets and Trading account liabilities, respectively. The MHFG Group provided and/or accepted cash collateral for derivative transactions under master netting agreements. The cash collateral, which was not offset against derivative positions, was included in Other assets and Other liabilities, respectively, of which the amounts were ¥1,108 billion and ¥764 billion at March 31, 2021, and ¥1,549 billion and ¥1,076 billion at March 31, 2022, respectively. Hedging activities In order to qualify for hedge accounting, a derivative must be considered highly effective at reducing the risk associated with the exposure being hedged. Each derivative must be designated as a hedge, with documentation of the risk management objective and strategy, including identification of the hedging instrument, the hedged item and the risk exposure, and how effectiveness is to be assessed prospectively and retrospectively. The extent to which a hedging instrument is effective at achieving offsetting changes in fair value or cash flows must be assessed at least quarterly. The MHFG Group’s hedging activities include net investment hedges. Net investment hedges The MHFG Group uses forward foreign exchange contracts and foreign currency-denominated debt instruments to protect the value of net investments in non-Japanese The following table summarizes gains and losses information related to net investment hedges for the fiscal years ended March 31, 2020, 2021 and 2022: Gains (losses) recorded in other comprehensive income (“OCI”) 2020 2021 2022 (in millions of yen) Financial instruments hedging foreign exchange risk 418 1,483 (1,267 ) Total 418 1,483 (1,267 ) Note: No amount related to the net investment hedges was reclassified from Accumulated other comprehensive income to earnings for the fiscal year ended March 31, 2022. Related million were reclassified from Accumulated other comprehensive income to earnings for the fiscal years ended March 31, 2020, 2021, respectively. Derivative instruments not designated or qualifying as hedges The MHFG Group enters into the following derivative transactions that do not qualify for hedge accounting with a view to implementing risk management strategies: (1) interest-rate swap transactions for the purpose of economically managing the interest-rate risks in deposits, loans etc., (2) currency swap transactions for the purpose of economically managing the foreign exchange risk of these assets, and (3) credit derivatives for the purpose of economically managing the credit risk in loans, residential mortgage-backed securities (“RMBS”), commercial mortgage-backed securities (“CMBS”), collateralized loan obligations (“CLO”) and other similar assets. Such derivatives are accounted for as trading positions. The changes in fair value of these instruments are primarily recorded in Trading account gains (losses)—net, even though they are used to mitigate or transform the risk of exposures arising from banking activities. The net gains (losses) resulting from changes in the fair value of certain credit derivatives where the Group purchases protection to mitigate its credit risk exposure, related to its corporate loan portfolio, is recorded in Other noninterest income (expenses). The following table summarizes gains and losses on derivatives not designated or qualifying as hedges during the fiscal years ended March 31, 2020, 2021 and 2022: Gains (losses) recorded in income 2020 2021 2022 (in millions of yen) Interest rate contracts 388,289 (27,893 ) (130,312 ) Foreign exchange contracts (111,920 ) 115,181 145,979 Equity-related contracts 217,744 (209,488 ) 728,226 Credit-related contracts (Note) 8,046 (58,602 ) (13,877 ) Other contracts (21,143 ) 23,680 7,762 Total 481,016 (157,122 ) 737,778 Note: Amounts include the net gains (losses) of million, ¥(2,956) million and ¥(605) million on the credit derivatives economically managing the credit risk of loans during the fiscal years ended March 31, 2020, 2021 and 2022, respectively. Credit derivatives A credit derivative is a bilateral contract between a seller and a buyer of protection against the credit risk of a particular entity. Credit derivatives generally require that the seller of credit protection make payments to the buyer upon the occurrence of predefined credit events, which include bankruptcy, dissolution or insolvency of the referenced entity. The MHFG Group either purchases or writes protection on either a single name or a portfolio of reference credits. The Group enters into credit derivatives to help mitigate credit risk in its corporate loan portfolio and other cash positions, to take proprietary trading positions, and to facilitate client transactions. The notional amount of credit derivatives represents the maximum potential amount of future payments the seller could be required to make. If the predefined credit event occurs, the seller will generally have a right to collect on the underlying reference credit and the related cash flows, while being liable for the full notional amount of credit protection to the buyer. The Group manages credit risk associated with written protection by purchasing protection with identical or similar underlying reference credits, which substantially offsets its exposure. Thus, the notional amount is not necessarily a reliable indicator of the Group’s actual loss exposure. The following table summarizes the notional and fair value amounts of credit derivatives at March 31, 2021 and 2022: 2021 2022 Notional amount Fair value Notional amount Fair value (in billions of yen) Credit protection written: Investment grade 3,687 71 3,045 38 Non-investment 872 17 2,122 54 Total 4,559 88 5,167 92 Credit protection purchased 5,872 (107 ) 6,690 (95 ) Note: The rating scale is based upon either the external ratings or the internal ratings of the underlying reference credit. The lowest investment grade rating is considered to be BBB - non-investment Non-investment The following table shows the maximum potential amount of future payments for credit protection written by expiration period at March 31, 2021 and 2022: Maximum payout/Notional amount 2021 2022 (in billions of yen) One year or less 249 245 After one year through five years 4,184 4,785 After five years 126 137 Total 4,559 5,167 Note: The maximum potential amount of future payments is the aggregate notional amount of the credit derivatives where the Group wrote the credit protection, and it has not been reduced by the effect of any amounts that the Group may possibly collect on the underlying assets and the related cash flows, nor netted against that of credit protection purchased. Credit-related contingent features Certain of the MHFG Group’s derivative instruments contain provisions that require the Group’s debt to maintain an investment grade credit rating from the major credit rating agencies. If the Group’s debt credit rating were to fall below investment grade, the counterparties to the derivative instruments could request immediate payment or demand immediate and ongoing full overnight collateralization on derivative instruments which are in net liability positions for the Group. The following table shows the quantitative information about derivative instruments with credit-risk-related contingent features at March 31, 2021 and 2022: 2021 2022 (in billions of yen) Aggregate fair value of derivative instruments with credit-risk-related contingent features in net liability positions 780 1,149 Collateral provided to counterparties in the normal course of business 584 1,164 Amount required to be posted as collateral or settled immediately if credit-risk-related contingent features were triggered 196 — Note: There was no amount that the Group would be required to post as collateral or settle immediately on March 31, 2022.

Commitments and contingencies

Commitments and contingencies	12 Months Ended
	Mar. 31, 2022
Commitments and contingencies	23. Commitments and contingencies Obligations under guarantees The MHFG Group provides guarantees or indemnifications to counterparties to enhance their credit standing and enable them to complete a variety of business transactions. A guarantee represents an obligation to make payments to third parties if the counterparty fails to fulfill its obligation under a borrowing arrangement or other contractual obligation. The types of guarantees under ASC 460, “Guarantees” (“ASC 460”) provided by the MHFG Group are described below. Performance guarantees Performance guarantees are issued to guarantee customers’ performance under contractual arrangements such as a tender bid on a construction project or the completion of a construction project. Guarantees on loans Guarantees on loans include obligations to guarantee the customers’ borrowing contracts. The MHFG Group is required to make payments to the guaranteed parties in the event that customers fail to fulfill obligations under the contracts. Guarantees on securities Guarantees on securities include obligations to guarantee securities, such as bonds issued by customers. Other guarantees Other guarantees include obligations to guarantee customers’ payments, such as tax payments. Guarantees for the repayment of trust principal The MHFG Group provides certain trust products with guarantees for the repayment of trust principal, e.g., loan trusts and certain jointly operated designated money trusts. Pursuant to Japanese trust-related laws, trustees are prohibited from compensating beneficiaries for any loss in the beneficial interests in each trust. However, under a special condition of the Japanese trust-related laws, trust banks as trustees are allowed to enter into an agreement to provide compensation for any loss in the principal of the trust. The MHFG Group manages and administers the trust assets to minimize exposures against losses from the guarantees for the repayment of trust principal, including writing-off Part of the trust account profits is set aside as a reserve in trust accounts to absorb losses in the trust asset portfolios in accordance with relevant Japanese laws concerning the trust business and/or trust agreements. Statutory reserves for loan trusts and reserves for jointly operated designated money trusts are calculated based on the trust principal or the balance of loans and other assets in the trust accounts. Since the probability of principal indemnification is considered to be remote, the MHFG Group had no related reserve for credit losses recorded in its consolidated financial statements. Liabilities of trust accounts The MHFG Group, as trustee, may enter into an agreement with a third party who is not the party to the relevant trust agreement to the extent necessary to handle the trust affairs for the purpose of fulfilling the objectives of the trust and, as such, the trustee shall be allowed to assume certain liabilities. Pursuant to Japanese trust-related laws, the trustee is ultimately liable to pay those liabilities out of its proprietary assets in the event that the trust assets are insufficient to cover those liabilities. The amount of trust liabilities rarely exceeds the amount of trust assets and, therefore, those liabilities are generally covered by the corresponding trust assets. To avoid the demand for payment out of the proprietary assets, the trustee can enter into a special covenant of limited liability under which the trust creditors agree to limit the trustee’s liability to the value of the trust assets and to waive the right for compulsory execution against the trustee’s proprietary assets. The MHFG Group regularly monitors the condition of trust accounts to minimize exposures against making payment. The amounts of such liabilities in the trust accounts, excluding those with the special covenant of limited liability, are presented in the tables below. Liabilities of trust accounts principally include obligations to return collateral under security lending transactions and other transactions. Derivative financial instruments Certain written options and credit default swaps are deemed guarantees pursuant to the definition of guarantees in ASC 460 if these contracts require the MHFG Group to make payments to counterparties based on changes in an underlying instrument or index that is related to an asset, a liability, or an equity security of the counterparties. The MHFG Group’s payments could involve a gross settlement or a net settlement. Because it is difficult in practice to determine whether the counterparty has the asset, the liability or the equity security relating to the underlying, the MHFG Group has decided to include all credit default swaps and written options, excluding written options outside the scope of ASC 460, in the guarantee disclosures. The MHFG Group records all guarantees and similar obligations subject to ASC 460 at fair value in the consolidated balance sheets at the inception of the guarantee. The total carrying amount of guarantees and similar obligations at March 31,2021 and 2022 was ¥160 billion and ¥443 billion, respectively, and was included in Other liabilities and Trading account liabilities. The total includes the carrying amounts of derivatives that are deemed to be guarantees, which amounted to ¥138 billion and ¥416 billion at March 31, 2021 and 2022, respectively. The table below summarizes the remaining term and maximum potential amount of future payments by type of guarantee at March 31, 2021 and 2022. The maximum potential amount of future payments disclosed below represents the contractual amounts that could be required to be repaid in the event of the guarantees being executed, without consideration of possible recoveries under recourse provisions or from collateral held. With respect to written options included in derivative financial instruments in the table below, in theory, the MHFG Group is exposed to unlimited losses; therefore, the table shows the notional amounts of the contracts as a substitute for the maximum exposure. The MHFG Group, when necessary, requires collateral such as cash, investment securities and real estate or third-party guarantees depending on the amount of credit risk involved, and employs means such as sub-participation 2021 Maximum potential/Contractual or Notional amount Amount by expiration period One year or After one year through five years After five years (in billions of yen) Performance guarantees 2,730 1,662 882 186 Guarantees on loans 348 242 84 22 Guarantees on securities 79 23 56 — Other guarantees 2,390 1,913 348 129 Guarantees for the repayment of trust principal 28 — 13 15 Liabilities of trust accounts 480 61 235 184 Derivative financial instruments 23,933 8,821 12,048 3,064 2022 Maximum potential/Contractual or Notional amount Amount by expiration period One year or After one year through five years After five years (in billions of yen) Performance guarantees 3,254 2,084 996 174 Guarantees on loans 419 314 42 63 Guarantees on securities 75 9 66 — Other guarantees 2,899 2,381 451 67 Guarantees for the repayment of trust principal 22 — 9 13 Liabilities of trust accounts 478 116 199 163 Derivative financial instruments 36,484 17,110 15,721 3,653 The table below presents the maximum potential amount of future payments of performance guarantees, guarantees on loans, guarantees on securities and other guarantees classified based on internal ratings at March 31, 2021 and 2022: 2021 2022 (in billions of yen) Investment grade 4,427 5,336 Non-investment 1,120 1,311 Total 5,547 6,647 Note: Investment grade in the internal rating scale generally corresponds to BBB- Other off-balance-sheet In addition to guarantees, the MHFG Group issues other off-balance-sheet Commitments to extend credit Commitments to extend credit are legally binding agreements to lend to customers on demand. They usually have set maturity dates. These agreements differ from guarantees in that they are generally revocable or contain provisions that enable the MHFG Group to avoid payment or reduce the amount of credit extended under certain conditions, such as the deterioration of the borrower’s financial condition or other reasonable conditions. The MHFG Group monitors the financial condition of the potential borrowers throughout the commitment period to determine whether additional collateral or changes in the terms of the commitment are necessary. Since many of these commitments to extend credit expire without being drawn upon, the total commitment amounts do not necessarily represent future cash requirements. Commitments to invest in securities Commitments to invest in securities include legally binding contracts to make additional contributions to investment funds, such as private equity funds in accordance with the terms of investment agreements. Commercial letters of credit Commercial letters of credit are issued in connection with customers’ trade transactions. Normally, the customers cannot receive the goods until they make payment to a bank, and therefore these commercial letters of credit are collateralized by the underlying goods. Upon issuance of commercial letters of credit, the MHFG Group monitors the credit risk associated with these transactions to determine if additional collateral is required. The table below summarizes the contractual amounts with regard to these undrawn commitments at March 31, 2021 and 2022: 2021 2022 (in billions of yen) Commitments to extend credit (Note) 93,999 92,203 Commercial letters of credit 797 1,422 Total 94,796 93,625 Note: Commitments to extend credit include commitments to invest in securities. Allowance for credit losses on off-balance-sheet The amounts of allowance for credit losses on off-balance-sheet Legal proceedings and investigations The MHFG Group is involved in normal collection proceedings initiated by the Group, other legal proceedings and investigations in the ordinary course of business. In accordance with ASC 450, the Group recognizes a liability for loss contingencies arising from such proceedings and investigations when a loss is probable and the loss amount or the range of the loss can be reasonably estimated. However, if a loss is reasonably possible but the range of loss is not probable and reasonably estimable, the Group does not recognize a liability but discloses the detail of such proceedings and investigations. Based on the information available as of the date of the consolidated financial statements, the Group believes that the outcome of the collection, legal proceedings and investigations will not have a significant adverse effect on the consolidated financial statements. Leases The MHFG Group is obligated under a number of lease arrangements. The Group’s lessee arrangements mainly consist of operating leases for real estate, such as office space, including its head office, and branches. Finance leases are not significant. Some of the Group’s operating leases include variable lease payments. The following table presents the consolidated balance sheet information related to operating leases as of March 31, 2021 and 2022: 2021 2022 (in millions of yen, except for remaining lease Right-of-use (Note) 611,533 570,171 Lease liabilities (Note) 636,541 593,339 Weighted average: Remaining lease term 15.6 years 15.5 years Discount rate 0.54 % 0.60 % Note: Right-of-use The following table presents lease cost and supplemental information related to operating leases for the fiscal years ended March 31, 2020, 2021 and 2022: 2020 2021 2022 (in millions of yen) Lease cost (Note) 126,840 119,453 111,907 Right-of-use 60,047 108,430 51,901 Operating cash flows 102,066 102,150 101,223 Note: Lease cost for operating leases are included in Occupancy expenses on the consolidated statements of income. The Group’s variable lease costs and costs for leases with terms of twelve months or less are not significant. The following table shows future lease payments under operating leases as of March 31, 2022: As of March 31, 2022 (in millions of yen) Fiscal year ending March 31: 2023 82,330 2024 60,138 2025 52,311 2026 41,991 2027 32,854 2028 and thereafter 347,734 Total lease payments 617,358 Amount representing interest 24,019 Total lease liabilities for operating leases 593,339

Variable interest entities and

Variable interest entities and securitizations	12 Months Ended
	Mar. 31, 2022
Text Block [Abstract]
Variable interest entities and securitizations	24. Variable interest entities and securitizations Variable interest entities In the normal course of business, the MHFG Group is involved with VIEs primarily through the following types of transactions: asset-backed commercial paper/loan programs, asset-backed securitizations, investments in securitization products, investment funds, trust arrangements, structured finance, and funding vehicles. The Group consolidates certain of these VIEs, where the Group is deemed to be the primary beneficiary because it has both (1) the power to direct the activities of the VIE that most significantly impact the VIE’s economic performance and (2) the obligation to absorb losses or the right to receive benefits that could potentially be significant to the VIE. The MHFG Group reassesses whether it is the primary beneficiary on an ongoing basis as long as the Group has any continuing involvement with the VIE. There are also other VIEs, where the Group has determined that it is not the primary beneficiary but has significant variable interests. In evaluating the significance of the variable interests, the Group takes into consideration the extent of its involvement with each VIE, such as the seniority of its investments, the share of its holding in each tranche and the variability it expects to absorb, as well as other relevant facts and circumstances. The likelihood of loss is not necessarily relevant to the determination of significance, and therefore, “significant” does not imply that there is high likelihood of loss. The maximum exposure to loss that is discussed in this section refers to the maximum loss that the Group could possibly be required to record in its consolidated statements of income as a result of its involvement with the VIEs. This represents exposures associated with both on-balance-sheet off-balance-sheet The table below shows the consolidated assets of the Group’s consolidated VIEs as well as total assets and maximum exposure to loss for its significant unconsolidated VIEs, in which the Group has determined that its maximum exposure to loss is greater than specific thresholds or meets certain other criteria as of March 31, 2021 and 2022: Consolidated VIEs Significant unconsolidated VIEs 2021 Consolidated assets Total assets Maximum exposure to loss (in billions of yen) Asset-backed commercial paper/loan programs 2,628 — — Asset-backed securitizations 921 127 48 Investments in securitization products 390 — — Investment funds 2,299 3,219 768 Trust arrangements and other 5,535 — — Total 11,773 3,346 816 Consolidated VIEs Significant unconsolidated VIEs 2022 Consolidated assets Total assets Maximum exposure to loss (in billions of yen) Asset-backed commercial paper/loan programs 2,709 — — Asset-backed securitizations 1,363 190 90 Investments in securitization products 388 — — Investment funds 1,816 3,392 719 Trust arrangements and other 5,299 — — Total 11,575 3,582 809 As of March 31, 2021 and 2022, the noncontrolling interests in consolidated VIEs amounted to ¥464 billion and ¥ 388 The Group has not provided financial or other support to consolidated or unconsolidated VIEs that the Group was not previously contractually required to provide. The tables below present the carrying amounts and classification of assets and liabilities on the MHFG Group’s balance sheets that relate to its variable interests in significant unconsolidated VIEs, as of March 31, 2021 and 2022: Assets on the MHFG Group’s balance sheets related to unconsolidated VIEs: 2021 2022 (in billions of yen) Trading account assets 127 143 Investments 513 430 Loans 66 92 Total 706 665 Liabilities on the MHFG Group’s balance sheets and maximum exposure to loss related to unconsolidated VIEs: 2021 2022 (in billions of yen) Payables under securities lending transactions 53 54 Trading account liabilities 2 2 Total 55 56 Maximum exposure to loss (Note) 816 809 Note: This represents the maximum amount the Group could possibly be required to record in its consolidated statements of income associated with on-balance-sheet off-balance-sheet In the table above the nature of the Group’s variable interest can take different forms, as described further in the notes below. Additionally the Group’s exposure to the obligations of VIEs is generally limited to its interest in these entities. In certain instances the Group provides undrawn commitments to the VIEs. The Group’s maximum exposure to loss presented in the table above does not include the benefit of offsetting financial instruments that are held to mitigate the risks associated with these variable interests. Furthermore, the Group’s maximum exposure to loss presented in the table above is not reduced by the amount of collateral held as part of the transaction with the VIE or any party to the VIE directly against a specific exposure to loss. Asset-backed commercial paper/loan programs The MHFG Group manages several asset-backed commercial paper/loan programs that provide its clients with off-balance-sheet responsible for liability management. In addition, through the liquidity and credit support facilities provided to the VIEs, the Group has the obligation to absorb losses that could potentially be significant to the VIEs. Therefore, the Group consolidates such VIEs. Asset-backed securitizations The MHFG Group acts as an arranger of various types of structured finance schemes to meet its clients’ needs for off-balance-sheet In addition, the MHFG Group establishes several single-issue and multi-issue special purpose entities that issue collateralized debt obligations (“CDO”) or CLO, synthetic CDO/CLO or other repackaged instruments to meet clients’ and investors’ financial needs. The MHFG Group also arranges securitization transactions including CMBS, RMBS and others. In these transactions, the MHFG Group acts as an underwriter, placement agent, asset manager, derivatives counterparty, and/or investor in debt and equity instruments. In these cases, the MHFG Group considers that these variable interests are not significant as the MHFG Group does not have material balance sheet or off-balance The MHFG Group established certain VIEs to securitize its own mortgage loans. The Group provides servicing for and holds retained subordinated beneficial interests in the securitized mortgage loans. In addition, the Group retains credit exposure in the form of guarantees on these loans. In its role as a servicer, the Group has the power to direct the entity’s activities that most significantly impact the entity’s economic performance by managing defaulted mortgage loans. In addition, through its retained interests and its aforementioned involvement as a guarantor, the Group has the obligation to absorb losses and the right to receive benefits that could potentially be significant to the entity. Therefore, the Group consolidates such VIEs. The MHFG Group started Tender Option Bond (“TOB”) programs in the fiscal year ended March 31, 2020, which are associated with trusts that hold highly-rated, fixed-rate and tax-exempt non-customer non-customer customer TOB trusts and the residual holders of customer TOB trusts are obligated to reimburse the Group for any payment the Group makes under those liquidity and credit support facilities. In non-customer Investments in securitization products The MHFG Group invests in, among other things, various types of CDO/CLO, synthetic CDO/CLO and repackaged instruments, CMBS and RMBS arranged by third parties for the purpose of generating current income or capital appreciation, which all utilize entities that are deemed to be VIEs. By design, such investments were investment grade at issuance and held by a diverse group of investors. The potential loss amounts of the securities and the loans are generally limited to the amounts invested because the Group has no contractual involvement in such VIEs beyond its investments. Since the Group is involved in these VIEs only as an investor, the Group does not ordinarily have the power to direct the VIEs’ activities that most significantly impact the VIEs’ economic performance. Similar to the criteria noted in the asset-backed securitization section, the Group views this investment activity to be “significant” when it has a large investment share and/or provides loans to the VIEs. The Group consolidates VIEs, where the transactions are tailored by the third-party arrangers to meet the Group’s needs as a main investor, who is ultimately deemed to have the power to determine which assets are to be held by the VIEs. The Group also invests in certain beneficial interests issued by VIEs which hold real estate that the Group utilizes. In addition to these variable interests, when the Group has the power including the sole unilateral ability to liquidate the VIEs, the Group consolidates such VIEs. Investment funds The MHFG Group invests in various investment funds, including securities investment trusts, which collectively invest in equity and debt securities that include listed Japanese securities and investment grade bonds. Investment advisory companies or fund management companies, including the Group’s subsidiaries and affiliates, administer and make investment decisions about such investment funds. The Group considers that it is a “significant” variable interest when the Group’s investment share is greater than threshold. The Group consolidates certain investment funds where it is deemed to be the primary beneficiary. The Group determines whether it is the primary beneficiary by evaluating whether it has both (1) the power to make investment decisions about the investment funds and (2) the obligation to absorb losses or the right to receive benefits that could potentially be significant to the investment funds. The Group consolidates certain investment funds where it is deemed to be the primary beneficiary. Trust arrangements The MHFG Group offers a variety of asset management and administration services under trust arrangements including security investment trusts, pension trusts and trusts used in the securitization of assets originated by and transferred to third parties. The Group receives trust fees for providing services as an agent or fiduciary on behalf of beneficiaries. In these cases, the MHFG Group considers that these variable interests are not significant except for its specific involvement as noted below; With respect to guaranteed principal money trust products, the MHFG Group assumes certain risks by providing guarantees for the repayment of principal as required by the trust agreements or relevant Japanese legislation. The MHFG Group manages entrusted funds primarily through the origination of high-quality loans and other credit-related products, investing in investment grade marketable securities such as Japanese government bonds and placing cash with the MHFG Group’s subsidiary trust banks. The Group has the power to determine which assets will be held by the VIEs or to manage these assets. In addition, through the principal guarantee agreements, the Group has the obligation to absorb losses that could potentially be significant to the VIEs. Therefore, the Group consolidates such VIEs. However, the MHFG Group does not consolidate certain guaranteed principal money trusts, which invest all the entrusted funds in the MHFG Group itself, as the Group has determined that it has no variable interests. See Note 23 “Commitments and contingencies” for the balances of guaranteed trust principal that are not consolidated at March 31, 2021 and 2022. With respect to non-guaranteed non-guaranteed The MHFG Group has established a trust in August 2020, which holds the Group’s housing loans and in turn issues beneficiary interests to the Group, as a result from Special Funds-Supplying Operations implemented by the Bank of Japan to facilitate financing in response to COVID-19. Special purpose entities created for structured finance The MHFG Group is involved in real estate, commercial aircraft and other vessel and machinery and equipment financing to VIEs and financing in securitized receivable. As the Group typically only provides senior financing with credit enhanced by subordinated interests and may sometimes act as an interest rate swap counterparty, the Group has determined that it does not have the power to direct the activities of the VIEs that most significantly impact the VIEs’ economic performance, or it does not have significant variable interests. Therefore, the Group does not consolidate such VIEs. Funding Vehicles The MHFG Group has established several wholly-owned off-shore 367 Securitization The MHFG Group engages in securitization activities and securitizes mortgage loans, other loans, government and corporate securities and other types of financial assets in the normal course of business. In these securitization transactions, the Group records the transfer of a financial asset as a sale when all the accounting criteria for a sale under ASC 860 are met. These criteria are (1) the transferred financial assets are legally isolated from the Group’s creditors, (2) the transferee or beneficial interest holder has the right to pledge or exchange the transferred financial assets, and (3) the Group does not maintain effective control over the transferred financial assets. If all the criteria are not met, the transfer is accounted for as a secured borrowing. For the fiscal years ended March 31, 2020, 2021 and 2022, the MHFG Group neither made significant transfers of financial assets nor recognized significant gains or losses in securitization transactions accounted for as sales. The Group did not retain significant interests in securitization transactions accounted for as sales as of March 31, 2021 and 2022. There are certain transactions where transfers of financial assets do not qualify for the aforementioned sales criteria and are accounted for as secured borrowings. These transferred assets continue to be carried on the consolidated balance sheets of the MHFG Group. Such assets are associated with securitization transactions and loan participation transactions, which amounted to ¥176 billion and ¥181 billion as of March 31, 2021, and ¥ 137 220

Noninterest income

Noninterest income	12 Months Ended
	Mar. 31, 2022
Noninterest income	25. Noninterest income Details of Noninterest income for the fiscal years ended March 31, 2020, 2021 and 2022 are as follows: 2020 2021 2022 (in millions of yen) Fee and commission income: Securities-related business (1) 139,124 170,216 184,014 Deposits-related business (1) 14,668 15,162 15,358 Lending-related business (2)(4) 142,752 158,921 162,953 Remittance business (1) 112,275 109,111 103,979 Asset management business (1) 98,720 104,753 122,014 Trust-related business (1) 129,298 122,215 141,365 Agency business (1) 31,879 31,331 36,899 Guarantee-related business (3) 28,974 31,665 35,296 Fees for other customer services (1) 170,195 169,310 178,122 Total Fee and commission income 867,885 912,684 980,000 Foreign exchange gains (losses)—net (3) 44,345 89,267 91,611 Trading account gains (losses)—net (2) 745,692 120,596 (491,947 ) Investment gains (losses)—net: Debt securities (3) 31,032 (22,032 ) (14,777 ) Equity securities (3) (557,391 ) 850,567 (60,563 ) Equity in earnings (losses) of equity method investees—net (3) 34,012 31,027 34,587 Gains on disposal of premises and equipment (3) 2,583 7,125 9,943 Other noninterest income (2)(5) 139,582 52,086 120,936 Total 1,307,740 2,041,320 669,790 Notes: (1) These amounts are revenues from contracts within the scope of ASC 606, “Revenue from contracts with customers” (“ASC 606”). (2) Part of these amounts are considered to be revenues from contracts that are within the scope of ASC 606. (3) These amounts are revenues from contracts that do not meet the scope of ASC 606. (4) Most of the lending-related fees such as commitment fees and arrangement fees are not within the scope of ASC 606. (5) These amounts include the net unrealized gains resulting from changes in fair values of structured notes that contain embedded derivatives. See Note 27 “Fair value” for further details. Certain Fee and commission income, Trading account gains (losses)—net and Other noninterest income outlined in the table above are considered to be revenues from contracts that are within the scope of ASC 606. The MHFG Group disaggregates Fee and commission income, which is the main part of revenues within the scope of ASC 606, by type of business or service in the table above. Fee and commission income For the MHFG Group’s accounting policy for the recognition of Fee and commission income, see Note 1 “Basis of presentation and summary of significant accounting policies.” Trust-related business fees consist of trust fees earned primarily through fiduciary asset management and administrative service and other trust-related fees, which amounted to ¥54 billion and ¥75 billion for the fiscal year ended March 31, 2020, respectively, ¥51 billion and ¥71 billion for the fiscal year ended March 31, 2021, respectively, and ¥56 billion and ¥85 billion for the fiscal year ended March 31, 2022, respectively. Trading account gains (losses)—net and Other noninterest income In addition to Fee and commission income, Trading account gains (losses)—net and Other noninterest income include certain revenues within the scope of ASC 606. Underwriting fees from trading securities, which amounted to ¥60 billion, ¥86 billion and ¥83 billion for the fiscal years ended March 31, 2020, 2021 and 2022, respectively, are within the scope of ASC 606 and accounted for in Trading account gains (losses)—net. Underwriting fees are primarily recognized on the date which all the considerations of the transaction are fixed. For the fiscal years ended March 31, 2020, 2021 and 2022, approximately ¥24 billion, ¥15 billion and ¥15 billion, respectively, of Other noninterest income were within the scope of ASC 606. Credit card interchange fees are within the scope of ASC 606 and accounted for in Other noninterest income. Credit card interchange fees are earned on credit card transactions conducted through payment networks and recognized upon settlement of the credit card payment transactions. Contract balances relating to revenues from contracts with customers subject to ASC 606 Contract assets and receivables from contracts with customers subject to ASC 606 are recognized in Accrued income or accounts receivable of Other assets. As of March 31, 2021 and 2022, the balance of contract assets was not material. Contract liabilities are recognized in unearned income of Other liabilities. As of March 31, 2021 and 2022, the balance of contract liabilities was not material. Remaining performance obligations relating to revenues from contracts with customers subject to ASC 606 Remaining performance obligations are services that the MHFG Group has committed to provide in the future in connection with its contracts with customers. As of March 31, 2021 and 2022, the amount of expected revenues from current obligations to provide services in the future was not material

Trading account gains and losse

Trading account gains and losses	12 Months Ended
	Mar. 31, 2022
Trading Account Gains And Losses [Abstract]
Trading account gains and losses	26. Trading account gains and losses The MHFG Group performs trading activities through market making, sales, and arbitrage. Accordingly, Trading account gains (losses)—net include gains and losses from transactions undertaken for trading purposes, including both market making for customers and proprietary trading, or transactions through which the Group seeks to capture gains arising from short-term changes in market value. Trading account gains (losses)—net also include gains and losses related to changes in the fair value of derivatives and other financial instruments not eligible for hedge accounting under U.S. GAAP that are utilized to offset mainly interest rate risk related to the Group’s various assets and liabilities, as well as gains and losses related to changes in the fair value of foreign currency-denominated 2020 2021 2022 (in millions of yen) Trading account gains (losses)—net: Trading securities 267,514 274,762 (1,230,330 ) Derivative contracts: Interest rate contracts 388,289 (27,893 ) (130,312 ) Foreign exchange contracts (1) (111,920 ) 115,181 145,979 Equity-related contracts 217,744 (209,488 ) 728,226 Credit-related contracts (2) 5,208 (55,646 ) (13,272 ) Other contracts (21,143 ) 23,680 7,762 Total 745,692 120,596 (491,947 ) Foreign exchange gains (losses)—net (3) 44,345 89,267 91,611 Net trading gains (losses) 790,037 209,863 (400,336 ) Notes: (1) Amounts include gains and losses on currency swaps. ( 2 Amounts do not include the net gains (losses) of ¥2,838 million, ¥(2,956) million and ¥(605) million on the credit derivatives economically managing the credit risk of loans during the fiscal years ended March 31, 2020, 2021 and 2022, respectively. The net gains (losses) is recorded in Other noninterest income (expenses). ( 3 Amounts include realized and unrealized gains and losses on both derivative instruments and nonderivative instruments. Amounts on derivative instruments include gains and losses on forward foreign exchange contracts and currency options. Amounts on nonderivative instruments include translation gains and losses related to foreign currency-denominated debt securities reported as Trading securities.

Fair value

Fair value	12 Months Ended
	Mar. 31, 2022
Fair value	27. Fair value Fair value measurements ASC 820 defines fair value as the exchange price that would be received for an asset or paid to transfer a liability (an exit price) in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants on the measurement date. ASC 820 also establishes a fair value hierarchy which requires an entity to maximize the use of observable inputs and minimize the use of unobservable inputs when measuring fair value. In addition, ASC 820 precludes (1) the deferral of gains and losses at inception of certain derivative contracts whose fair value was not evidenced by market-observable data, and (2) the use of block discounts when measuring the fair value of instruments traded in an active market, which were previously applied to large holdings of publicly traded financial instruments. Fair value hierarchy ASC 820 specifies a hierarchy of valuation techniques based on whether the inputs to those valuation techniques are observable or unobservable. The standard describes three levels of inputs that may be used to measure fair value: Level 1 Quoted prices in active markets for identical assets or liabilities. Level 1 assets and liabilities include debt and equity securities and derivative contracts that are traded in an active exchange market. Level 2 Observable inputs other than Level 1 prices, such as quoted prices for similar assets or liabilities; quoted prices in markets that are not active; or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the assets or liabilities. Level 2 assets and liabilities include debt securities with quoted prices that are traded less frequently than exchange-traded instruments. If no quoted market prices are available, the fair values of debt securities and over-the-counter Level 3 Unobservable inputs that are supported by little or no market activity and that are significant to the fair value of the assets or liabilities. Level 3 assets and liabilities include financial instruments whose values are determined using pricing models, discounted cash flow methodologies, or similar techniques, as well as instruments for which the determination of fair value requires significant management judgment or estimation. Valuation process The MHFG Group has established valuation policies which govern the principles of fair value measurements and the authority and duty of each department. The Group has also established procedure manuals which describe valuation techniques and related inputs for determining the fair values of various financial instruments. The policies require that the measurement of fair values be carried out in accordance with the procedures performed by the risk management departments or the back offices which are independent from the front offices. The policies also require the risk management departments to check and verify whether the valuation methodologies defined in the procedure manuals are fair and proper and the internal audit departments to periodically review the compliance with the procedures throughout the Group. Although the valuation methodologies and related inputs are consistently used from period to period, a change in the market environment sometimes leads to a change in the valuation methodologies and the inputs. For instance, a change in market liquidity due to a delisting or a new listing is one of the key drivers of revisions to the valuation methodologies and the inputs. The key drivers also include the availability or the lack of market observable inputs and the development of new valuation methodologies. Price verification performed through the Group’s internal valuation process has an important role in identifying whether the valuation methodologies and the inputs need to be changed. The internal valuation process over the prices broker-dealers provide, primarily for Japanese securitization products, is described in more detail below in Available-for-sale requires the revision of the valuation policies and procedure manuals, which is required to be approved by the appropriate authority, either the CEO, the head of risk management, and/or the head of accounting, depending on the nature and characteristics of the change. The following is a description of valuation methodologies and inputs used for assets and liabilities measured at fair value on a recurring basis, including the general classification of such instruments pursuant to the fair value hierarchy and the MHFG Group’s valuation techniques used to measure fair values. During the fiscal year ended March 31, 2022, there were no significant changes made to the Group’s valuation techniques and related inputs. Trading securities and trading securities sold, not yet purchased When quoted prices for identical securities are available in an active market, the Group uses the quoted prices to measure the fair values of securities and such securities are classified in Level 1 of the fair value hierarchy. Level 1 securities include highly liquid government bonds and equity securities. When quoted prices for identical securities are available, but not actively traded, such securities are classified in Level 2 of the fair value hierarchy. When no quoted market prices are available, the Group estimates fair values by using pricing models with inputs that are observable in the market and such securities are classified in Level 2 of the fair value hierarchy. Level 2 securities include Japanese local government bonds, corporate bonds, and commercial paper. When less liquid market conditions exist for securities, the quoted prices are stale or the prices from independent sources vary significantly, such securities are generally classified in Level 3 of the fair value hierarchy. The fair values of securitization products such as RMBS, CMBS, ABS, and CLO are determined primarily by using a discounted cash flow model. The key inputs used for the model include default rates, recovery rates, prepayment rates, and discount rates. Though most securitization products are classified in Level 2, if the significant inputs are unobservable or cannot be corroborated by observable market data, these financial instruments are classified in Level 3. Hedge funds the Group invests in are primarily multi strategy funds that employ a fundamental bottom-up start-up ten-year Derivative financial instruments Exchange-traded derivatives are valued using quoted market prices and consequently are classified in Level 1 of the fair value hierarchy. However, the majority of derivatives entered into by the Group are executed over-the-counter observability of the significant inputs to the model. Level 2 derivatives include plain vanilla interest rate and currency swaps and option contracts. Derivative contracts valued using significant unobservable correlation or volatility are classified in Level 3 of the fair value hierarchy. In addition, the Group records credit-risk valuation adjustments on over-the-counter over-the-counter Available-for-sale The fair values of available-for-sale non-binding Equity securities Equity securities mainly consist of marketable equity securities. The fair values of the marketable equity securities are based upon quoted market prices for identical equity securities trading as securities in an active market. Equity securities also include investments in certain investment funds measured using the NAV per share practical expedient including private equity funds and real estate funds. These securities are determined primarily using the same procedures described under Trading securities and trading securities sold, not yet purchased Other investments Other investments consist of investments held by consolidated investment companies. These companies typically hold investments in marketable and non-marketable marketable equity securities is based upon quoted market prices. The fair value of the non-marketable Non-marketable Long-term debt Fair value accounting is elected for certain long-term debt instruments with embedded derivatives. The fair values are determined using a discounted cash flow model that considers the embedded derivatives and the terms and payment structures of the notes. The fair values of the derivatives embedded in such notes are primarily derived by using the same procedures described in Derivative financial instruments above. Such notes are classified in Level or Level depending on the observability of the significant inputs into the model used to determine the fair value of the embedded derivatives. The Group also measures certain notes that contain embedded derivatives at fair value under the practicability exception. For these instruments, fair value is based on quot e of the fair value hierarchy. Items measured at fair value on a recurring basis Assets and liabilities measured at fair value on a recurring basis at March 31, 2021 and 2022, including those for which the MHFG Group has elected the fair value option, are summarized below: 2021 Level 1 Level 2 Level 3 Assets/ Liabilities measured at fair value (in billions of yen) Assets: Trading securities (1) : Japanese government bonds 1,923 11 — 1,934 Japanese local government bonds — 120 — 120 U.S. Treasury bonds and federal agency securities 3,544 604 — 4,148 Other foreign government bonds 775 500 — 1,275 Agency mortgage-backed securities — 4,727 — 4,727 Residential mortgage-backed securities — — 9 9 Certificates of deposit and commercial paper — 1,204 — 1,204 Corporate bonds and other (2) 34 1,638 1,033 2,705 Equity securities 1,220 326 29 1,575 Trading securities measured at net asset value (3) 431 Derivative financial instruments: Interest rate contracts 63 4,564 12 4,639 Foreign exchange contracts — 3,304 24 3,328 Equity-related contracts 170 339 22 531 Credit-related contracts — 91 3 94 Other contracts 10 6 17 33 2021 Level 1 Level 2 Level 3 Assets/ Liabilities measured at fair value (in billions of yen) Available-for-sale Japanese government bonds 20,598 323 — 20,921 Japanese local government bonds — 463 — 463 U.S. Treasury bonds and federal agency securities 911 — — 911 Other foreign government bonds 535 972 — 1,507 Agency mortgage-backed securities — 521 — 521 Residential mortgage-backed securities — 48 23 71 Commercial mortgage-backed securities — — 716 716 Japanese corporate bonds and other debt securities — 1,539 365 1,904 Foreign corporate bonds and other debt securities — 707 132 839 Equity securities: Equity securities with readily determinable fair values 3,375 104 — 3,479 Equity securities measured at net asset value (3) 121 Other investments 2 — 53 55 Total assets measured at fair value on a recurring basis 33,160 22,111 2,438 58,261 Liabilities: Trading securities sold, not yet purchased 2,138 488 — 2,626 Derivative financial instruments: Interest rate contracts 64 4,408 4 4,476 Foreign exchange contracts — 3,245 1 3,246 Equity-related contracts 224 117 43 384 Credit-related contracts — 112 1 113 Other contracts 7 9 17 33 Long-term debt (4) — 1,990 713 2,703 Total liabilities measured at fair value on a recurring basis 2,433 10,369 779 13,581 2022 Level 1 Level 2 Level 3 Assets/ Liabilities measured at fair value (in billions of yen) Assets: Trading securities (1) : Japanese government bonds 1,604 11 — 1,615 Japanese local government bonds — 145 — 145 U.S. Treasury bonds and federal agency securities 2,353 711 — 3,064 Other foreign government bonds 907 639 — 1,546 Agency mortgage-backed securities — 3,176 — 3,176 Residential mortgage-backed securities — — 8 8 Certificates of deposit and commercial paper — 640 — 640 Corporate bonds and other (2) 15 2,743 71 2,829 Equity securities 1,381 213 28 1,622 Trading securities measured at net asset value (3) 284 Derivative financial instruments: Interest rate contracts 89 4,513 22 4,624 Foreign exchange contracts — 4,404 32 4,436 Equity-related contracts 77 323 26 426 Credit-related contracts — 116 2 118 Other contracts 49 18 52 119 Available-for-sale Japanese government bonds 24,662 497 — 25,159 Japanese local government bonds — 420 — 420 U.S. Treasury bonds and federal agency securities 373 — — 373 Other foreign government bonds 363 973 — 1,336 Agency mortgage-backed securities — 451 — 451 Residential mortgage-backed securities — 40 18 58 Commercial mortgage-backed securities — 854 — 854 Japanese corporate bonds and other debt securities — 1,920 315 2,235 Foreign corporate bonds and other debt securities — 671 117 788 Equity securities: Equity securities with readily determinable fair values 3,094 61 — 3,155 Equity securities measured at net asset value (3) 210 Other investments 2 — 56 58 Total assets measured at fair value on a recurring basis 34,969 23,539 747 59,749 Liabilities: Trading securities sold, not yet purchased 3,054 2,035 — 5,089 Derivative financial instruments: Interest rate contracts 80 4,636 — 4,716 Foreign exchange contracts — 4,472 — 4,472 Equity-related contracts 122 183 40 345 Credit-related contracts — 120 1 121 Other contracts 28 36 52 116 Long-term debt (4) — 1,962 794 2,756 Total liabilities measured at fair value on a recurring basis 3,284 13,444 887 17,615 Notes: (1) Trading securities include foreign currency denominated securities for which the MHFG Group elected the fair value option. (2) The amount includes CLO and convertible bonds, which are classified in Level 3. (3) In accordance with ASC 820, certain investments that are measured at fair value using the net asset value per share (or its equivalent) practical expedient have not been classified in the fair value hierarchy. The fair value amounts presented for these classes of assets are intended to permit the reconciliation of the fair value hierarchy to the amounts presented in the statements of financial position. The amounts of unfunded commitments related to these investments at March 31, 2021 and 2022 were ¥55 billion and ¥68 billion, respectively. (4) Amounts represent items for which the Group elected the fair value option or for which it applied the practicability exception. Items measured at fair value on a recurring basis using significant unobservable inputs (Level 3) The following table presents a reconciliation for all assets and liabilities measured at fair value on a recurring basis using significant unobservable inputs (Level 3) for the fiscal years ended March 31, 2021 and 2022: 2021 April 1, 2020 Gains (losses) in Earnings Gains (losses) in OCI Transfers into Level 3 Transfers out of Level 3 Purchases Sales Issuances Settle- ments March 31, 2021 Change in unrealized gains (losses) still held (6) (in billions of yen) Assets: Trading securities: Residential mortgage- backed securities 10 — (2) — — — — — — (1 ) 9 — Corporate bonds and other 1,115 70 (2) — — (1 ) 443 (216 ) — (378 ) 1,033 65 Equity securities 30 1 (2) — — — 2 (3 ) — (1 ) 29 — Derivative financial instruments, net (1) Interest rate contracts (5 ) 4 (2) — — — — — — 9 8 13 Foreign exchange contracts 16 9 (2) — — — — — — (2 ) 23 10 Equity-related contracts (17 ) 1 (2) — — — — — — (5 ) (21 ) (17 ) Credit-related contracts (2 ) 4 (2) — 1 1 — — — (2 ) 2 1 Other contracts 1 — (2) — — — — — — (1 ) — — Available-for-sale Residential mortgage- 31 — (3) — (4) — — — — — (8 ) 23 — Commercial mortgage-backed securities 615 — (3) 1 (4) — — 181 (78 ) — (3 ) 716 — Japanese corporate bonds and other debt securities 157 (13 ) (3) 6 (4) — (22 ) 391 (118 ) — (36 ) 365 (8 ) Foreign corporate bonds and other debt securities 174 7 (3) 16 (4) 12 — 36 — — (113 ) 132 — Other investments 39 2 (3) — — — 38 (6 ) — (20 ) 53 1 Liabilities: Trading securities sold, not yet purchased — — (2) — — — (1 ) 1 — — — — Long-term debt 621 (66 ) (5) (19 ) (4) 20 (42 ) — — 374 (345 ) 713 (34 ) 2022 April 1, 2021 Gains (losses) in Earnings Gains (losses) in OCI Transfers into Level 3 Transfers out of Level 3 Purchases Sales Issuances Settle- ments March 31, 2022 Change in unrealized gains (losses) still held (6) (in billions of yen) Assets: Trading securities: Residential mortgage-backed securities 9 — (2) — — — — — — (1 ) 8 — Corporate bonds and other 1,033 7 (2) — — (452 ) 143 (72 ) — (588 ) 71 3 Equity securities 29 — (2) — — — — — — (1 ) 28 1 Derivative financial instruments, net (1) Interest rate contracts 8 11 (2) — — — — — — 3 22 (22 ) Foreign exchange contracts 23 8 (2) — — — — — — 1 32 7 Equity-related contracts (21 ) (11 ) (2) — — — — — — 18 (14 ) (23 ) Credit-related contracts 2 (3 ) (2) — — — — — — 2 1 (1 ) Other contracts — 1 (2) — — — — — — (1 ) — — Available-for-sale Residential mortgage-backed securities 23 — (3) — (4) — — — — — (5 ) 18 — Commercial mortgage-backed securities 716 5 (3) (5 ) (4) — (689 ) 62 (60 ) — (29 ) — — Japanese corporate bonds and other debt securities 365 (20 ) (3) 1 (4) — (4 ) 11 — — (38 ) 315 (19 ) Foreign corporate bonds and other debt 132 — (3) 7 (4) — (4 ) 47 — — (65 ) 117 1 Other investments 53 2 (3) — — — 37 (3 ) — (33 ) 56 (2 ) Liabilities: Trading securities sold, not yet purchased — — (2) — — — — — — — — — Long-term deb t 713 61 (5) 1 (4) 4 (6 ) — — 534 (389 ) 794 77 Notes: (1) Total Level 3 derivative exposures have been netted on the table for presentation purposes only. (2) Gains (losses) in Earnings are reported in Trading account gains (losses)—net, Foreign exchange gains (losses)—net or Other noninterest income (expenses). (3) Gains (losses) in Earnings are reported in Investment gains (losses)—net. (4) Gains (losses) in OCI are reported in Other comprehensive income (loss). (5) Gains (losses) in Earnings are reported in Other noninterest income (expenses). (6) Amounts represent total gains or losses recognized in earnings and OCI during the period. These gains or losses were attributable to the change in fair value relating to assets and liabilities classified as Level 3 that were still held at March 31, 2021 and 2022. The amounts of unrealized gains (losses) in OCI related to Available-for-sale Transfers between levels During the fiscal year ended March 31, 2021, the transfers into Level 3 included ¥ Available-for-sale Available-for-sale Available-for-sale billion of Long-term debt. Transfers out of Level 3 for Trading securities were primarily due to increased price transparency for certain Japanese corporate bonds. Transfers out of Level 3 for net Derivative liabilities were primarily due to changes in the observability of the inputs used to measure fair value of certain credit-related derivatives. Transfers out of Level 3 for Available-for-sale securities were primarily due to increased liquidity for certain Japanese corporate bonds and other debt securities. Transfers out of Level 3 for Long-term debt were primarily due to changes in the observability of the default rate when valuing certain structured notes. During the fiscal year ended March 31, 2022, the transfers out of Level 3 included ¥452 billion of Trading securities and billion of Available-for-sale securities. Assessing the significance of an input to the measurement requires judgment under ASC 820 and we previously evaluated that unobservable inputs in the valuation model were significant for certain Trading and Available-for-sale securities. During the year we refined the governance process over the fair value hierarchy by introducing certain tools, criteria and scenarios when considering if an input is significant to the fair value and whether the observable data was reliable. The transfers were supported by improvement in liquidity and price transparency since the start of the COVID-19 pandemic. Transfers out of Level 3 for Trading securities were primarily due to assessing the significance of unobservable inputs for certain corporate bonds and other debt securities. We changed the criteria for the quantitative sensitivity analysis for these securities to assess the significance of unobservable inputs, such as prepayment rate, default rate, and recovery rate. Transfers out of Level 3 for Available-for-sale securities were primarily due to assessing the significance of unobservable inputs for certain CMBS. We changed the criteria for the quantitative sensitivity analysis for these securities to assess the significance of unobservable inputs, such as discount margin. These methods and criteria are periodically verified by the middle and back office. Other than the above transfers between levels, during the fiscal year ended March 31, 2022, the transfers out of Level 3 included ¥4 billion of Available-for-sale billion of Long-term debt. Transfers out of Level 3 for Available-for-sale securities were primarily due to increased liquidity for certain Foreign corporate bonds and other debt securities. Transfers out of Level 3 for Long-term debt were primarily due to changes in the observability of the default rate when valuing certain structured notes. During the fiscal year ended March 31, 2022, the transfers into Level 3 included ¥ Quantitative information about Level 3 fair value measurements The following table presents information about significant unobservable inputs related to the MHFG Group’s material classes of Level 3 assets and liabilities at March 31, 2021 and 2022: 2021 Products/Instruments Fair value Principal valuation technique Unobservable inputs Range of input values Average (4) (in billions of yen, except for percentages and basis points) Trading securities and Available-for-sale Residential mortgage-backed securities 32 Discounted cash flow Price-based Prepayment rate Default rate Recovery rate Discount margin 2%–17% 0%–1% 100%–100% 28bps–170bps 7% 0% 100% 51bps Commercial mortgage-backed securities 716 Discounted cash flow Price-based Discount margin 5 bps 22bps Corporate bonds and other 1,530 Discounted cash flow Price-based Prepayment rate (1) Default rate (1) Recovery rate (1) Discount margin (1) Discount margin (2) 10%–18% 1%–24% 10%–68% 45bps–143bps 4bps–507bps 18% 2% 66% 115bps 284bps Derivative financial instruments, net: Interest rate contracts 8 Internal valuation model (3) IR – IR correlation 35 % – 76% Foreign exchange contracts 23 Internal valuation model (3) FX – IR correlation FX – FX correlation 23%–50% 43%–65% 30% 54% Equity-related contracts (21 ) Internal valuation model (3) Equity – IR correlation Equity correlation Equity volatility 25%–25% 0%–100% 8%–71% 25% 88% 41% Credit-related contracts 2 Internal valuation model (3) Default rate Credit correlation 0%–5% 40%–100% 1% 66% Other contracts — Internal valuation model (3) Commodity volatility 0%–63% 33% Long-term debt 713 Internal valuation model (3) IR – IR correlation 49 % 78% FX – IR correlation 23%–50% 36% FX – FX correlation 43%–65% 54% Equity – IR correlation 25%–25% 25% Equity – FX correlation -33%–50% 0% Equity correlation 0%–100% 88% Equity volatility 8%–71% 29% Default rate 0%–5% 1% Credit correlation 17%–100% 68% 2022 Products/Instruments Fair value Principal valuation technique Unobservable inputs Range of input values Average (4) (in billions of yen, except for percentages and basis points) Trading securities and Available-for-sale Residential mortgage-backed securities 26 Discounted cash flow Prepayment rate 0%–18% 6% Price-based Default rate 0%–0% 0% Recovery rate 100%–100% 100% Discount margin 30bps–167bps 53bps Corporate bonds and other debt securities 503 Discounted cash flow Prepayment rate (1) 6%–24% 24% Price-based Default rate (1) 0%–60% 1% Recovery rate (1) 10%–40% 39% Discount margin (1) 35bps–103bps 47bps Discount margin (2) 4bps–447bps 340bps Derivative financial instruments, net: Interest rate contracts 22 Internal valuation model (3) IR – IR correlation 23%–100% 75% Foreign exchange contracts 32 Internal valuation model (3) FX – IR correlation 11%–52% 31% FX – FX correlation 41%–65% 53% Equity-related contracts (14 ) Internal valuation model (3) Equity – IR correlation 25%–25% 25% Equity correlation 3%–100% 90% Equity volatility 13%–121% 47% Credit-related contracts 1 Internal valuation model (3) Default rate 0%–8% 1% Credit correlation 43%–100% 66% Other contracts — Internal valuation model (3) Commodity volatility 0%–89% 55% Long-term debt 794 Internal valuation model (3) IR – IR correlation 23%–100% 75% FX – IR correlation 11%–52% 39% FX – FX correlation 41%–65% 53% Equity – IR correlation 25%–25% 25% Equity – FX correlation -17%–17% 0% Equity correlation 3%–100% 90% Equity volatility 9%–121% 34% Default rate 0%–8% 1% Credit correlation 19%–100% 64% Notes: (1) These inputs are mainly used for determining the fair values of securitization products such as CDO, CLO and ABS, other than RMBS and CMBS. (2) This input is mainly used for determining the fair values of Japanese corporate bonds and foreign corporate bonds. (3) Internal valuation model includes discounted cash flow models and the Black-Scholes option pricing model. (4) Averages are calculated by weighting each input by the relative fair value of the respective financial instruments except for derivative related inputs where medians are used. IR = Interest rate FX = Foreign exchange Uncertainty of fair value measurements relating to unobservable inputs and interrelationships among unobservable inputs The following is a description of the uncertainty of the fair value measurements from the use of significant unobservable inputs and a description of interrelationships of the significant unobservable inputs used to measure the fair values of Level 3 assets and liabilities. (1) Prepayment rate The prepayment rate is the estimated rate at which voluntary unscheduled repayments of the principal of the underlying assets are expected to occur. The movement of the prepayment rate is generally negatively correlated with borrower delinquency. A change in prepayment rate would impact the valuation of the fair values of financial instruments either positively or negatively, depending on the structure of financial instruments. (2) Default rate The default rate is an estimate of the likelihood of not collecting contractual payments. An increase in the default rate would generally be accompanied by a decrease in the recovery rate and an increase in the discount margin. It would also generally impact the valuation of the fair values of financial instruments negatively. (3) Recovery rate The recovery rate is an estimate of the percentage of contractual payments that would be collected in the event of a default. An increase in recovery rate would generally be accompanied by a decrease in the default rate. It would also generally impact the valuation of the fair values of financial instruments positively. (4) Discount margin The discount margin is the portion of the interest rate over a benchmark market interest rate such as Tokyo Interbank Offered Rate (“TIBOR”) or swap rates. It primarily consists of a risk premium component which is the amount of compensation that market participants require due to the uncertainty inherent in the financial instruments’ cash flows resulting from credit risk. An increase in discount margin would generally impact the valuation of the fair values of financial instruments negatively. (5) Correlation Correlation is the likelihood of the movement of one input relative to another based on an established relationship. The change in correlation would impact the valuation of derivatives either positively or negatively, depending on the nature of the underlying assets. (6) Volatility Volatility is a measure of the expected change in variables over a fixed period of time. Some financial instruments benefit from an increase in volatility and others benefit from a decrease in volatility. Generally, for a long position in an option, an increase in volatility would result in an increase in the fair values of financial instruments. Items measured at fair value on a nonrecurring basis Certain assets and liabilities are measured at fair value on a nonrecurring basis. These assets and liabilities primarily include items that are measured at the lower of cost or fair value, and items that were initially measured at cost and have been written down to fair value as a result of impairment. The following table shows the fair value hierarchy for these items as of March 31, 2021 and 2022: 2021 Total Level 1 Level 2 Level 3 Aggregate cost (in billions of yen) Assets: Loans 85 — 3 82 167 Loans held-for-sale 22 — 21 1 23 Equity securities (without readily determinable fair values) 3 — — 3 4 Premises and equipment—net — — — — 7 Other assets 24 — — 24 34 Total assets measured at fair value on a nonrecurring basis 134 — 24 110 235 2022 Total Level 1 Level 2 Level 3 Aggregate cost (in billions of yen) Assets: Loans 81 — — 81 128 Loans held-for-sale 76 — 27 49 77 Equity securities (without readily determinable fair values) 4 — 3 1 4 Premises and equipment—net — — — — 13 Other ass e — — — — 3 Total assets measured at fair value on a nonrecurring basi s 161 — 30 131 225 Note: The fair values may not be current as of the dates indicated, but rather as of the date the fair value change occurred. Accordingly, the carrying values may not equal current fair value. Loans in the table above became nonaccrual and are measured based upon the observable market price of the loan, which is classified as Level 2, or the fair value of the underlying collateral, which is classified as Level 3. Loans held-for-sale Equity securities (without readily determinable fair values) in the table above consist of non-marketable non-marketable non-marketable non-marketable The fair values of non-marketable equity securities adjusted based on observed transaction prices are mainly classified as Level 2. Premises and equipment—net and Other assets in the table above have been impaired and written down to fair value. Fair value option The MHFG Group elected the fair value option for certain eligible financial instruments described below. Foreign currency denominated debt securities The MHFG Group elected the fair value option for foreign currency denominated debt securities to mitigate the volatility in earnings due to the difference in the recognition of foreign exchange risk between foreign currency denominated debt securities and financial liabilities. Following the election of the fair value option, these debt securities are reported as trading securities in Trading account assets. Certain hybrid financial instruments The MHFG Group issues structured notes as part of its client-driven activities. Structured notes are debt instruments that contain embedded derivatives. The Group elected the fair value option for certain structured notes to mitigate accounting mismatches and to achieve operational simplifications. Fair value option has only been elected for part of the portfolio as the Group would not achieve operational simplifications. In addition, the Group measures certain notes that contain embedded derivatives at fair value under the practicability exception. These notes continue to be reported in Long-term debt and interest on these notes continues to be reported in Interest expense on long-term debt based on the contractual rates. Only an immaterial amount included in Long-term debt in the statement of financial position is not eligible for fair value option. The differences between the aggregate fair value of these notes and the aggregate unpaid principal balance of such instruments were ¥14 billion and ¥90 billion at March 31, 2021 and 2022, respectively. The net unrealized gains (losses) resulting from changes in fair values of these notes recorded in Other noninterest income (expenses) were of ¥(10) billion and ¥38 billion for the fiscal years ended March 31, 2021 and 2022, respectively. Changes in fair value resulting from changes in instrument-specific credit risk were estimated by incorporating the Company’s current credit spreads observable in the bond market. Fair value of financial instruments ASC 825, “Financial Instruments” (“ASC 825”), requires the disclosure of the estimated fair value of financial instruments. The fair value of financial instruments is the amount that would be exchanged between willing parties, other than in a forced sale or liquidation. Quoted market prices, if available, are best utilized as estimates of the fair values of financial instruments. However, since no quoted market prices are available for certain financial instruments, fair values for such financial instruments have been estimated based on management’s assumptions, discounted cash flow models or other valuation techniques. Such estimation methods are described in more detail below. These estimates could be significantly affected by different sets of assumptions. There are certain limitations to management’s best judgment in estimating fair values of financial instruments and inhere

Offsetting of financial assets

Offsetting of financial assets and financial liabilities	12 Months Ended
	Mar. 31, 2022
Offsetting of financial assets and financial liabilities	28. Offsetting of financial assets and financial liabilities Derivatives The MHFG Group enters into master netting arrangements such as International Swaps and Derivatives Association, Inc. (“ISDA”) or similar agreements with counterparties to manage mainly credit risks associated with counterparty default. If the predetermined events including counterparty default occur, these enforceable master netting arrangements or similar agreements give the Group the right to offset derivative receivables and derivative payables and related financial collateral such as cash and securities with the same counterparty. Repurchase and resale agreements and securities lending and borrowing transactions Repurchase and resale agreements and securities lending and borrowing transactions are generally covered by industry standard master repurchase agreements and industry standard master securities lending agreements with netting terms to manage mainly credit risks associated with counterparty default. In the event of default by the counterparty, these agreements with netting terms provide the Group with the right to offset receivables and payables related to such transactions with the same counterparty, and to liquidate the collateral held. The following table provides information about the offsetting of financial assets and financial liabilities at March 31, 2021 and 2022. The table includes derivatives, repurchase and resale agreements, and securities lending and borrowing transactions that are subject to enforceable master netting arrangements or similar agreements irrespective of whether or not they are offset on the Group’s consolidated balance sheets. Amounts not offset on the balance sheet (3) Gross amounts recognized Gross amounts offset on the balance sheet Net amounts presented on the balance sheet (2) Financial instruments (4) Cash collateral Net amounts (in billions of yen) 2021 Assets (1) : Derivatives 8,625 — 8,625 (5) (6,323 ) (588 ) 1,714 Receivables under resale agreements 11,623 — 11,623 (6) (10,478 ) — 1,145 Receivables under securities borrowing transactions 2,694 — 2,694 (7) (2,621 ) — 73 Total 22,942 — 22,942 (19,422 ) (588 ) 2,932 Liabilities (1) : Derivatives 8,252 — 8,252 (5) (6,033 ) (933 ) 1,286 Payables under repurchase agreements 18,607 — 18,607 (6) (17,979 ) — 628 Payables under securities lending transactions 1,208 — 1,208 (7) (953 ) — 255 Total 28,067 — 28,067 (24,965 ) (933 ) 2,169 2022 Assets (1) : Derivatives 9,723 — 9,723 (5) (7,232 ) (891 ) 1,600 Receivables under resale agreements 12,751 — 12,751 (6) (11,437 ) — 1,314 Receivables under securities borrowing transactions 2,339 — 2,339 (7) (2,299 ) — 40 Total 24,813 — 24,813 (20,968 ) (891 ) 2,954 Liabilities (1) : Derivatives 9,770 — 9,770 (5) (6,716 ) (1,329 ) 1,725 Payables under repurchase agreements 20,070 — 20,070 (6) (19,366 ) — 704 Payables under securities lending transactions 1,361 — 1,361 (7) (1,164 ) — 197 Total 31,201 — 31,201 (27,246 ) (1,329 ) 2,626 Notes: (1) Amounts relating to master netting arrangements or similar agreements where the MHFG Group does not have the legal right of set-off over-the-counter OTC-cleared (2) Derivative assets and liabilities are recorded in Trading account assets and Trading account liabilities, respectively. (3) Amounts do not exceed the net amounts presented on the balance sheet and do not include the effect of overcollateralization, where it exists. (4) For derivatives, amounts include derivative assets or liabilities and securities collateral that are eligible for offsetting under enforceable master netting arrangements or similar agreements. (5) The amounts of derivative assets and liabilities subject to enforceable master netting arrangements or similar agreements were ¥8,168 billion and ¥7,652 billion, respectively, at March 31, 2021, and ¥9,326 billion and ¥9,235 billion, respectively, at March 31, 2022. (6) The amounts of Receivables under resale agreements and Payables under repurchase agreements subject to enforceable industry standard master repurchase agreements with netting terms were ¥10,551 billion and ¥18,321 billion, respectively, at March 31, 2021, and ¥11,537 billion and ¥19,505 billion respectively, at March 31, 2022. (7) The amounts of Receivables under securities borrowing transactions and Payables under securities lending transactions subject to enforceable industry standard master lending agreements with netting terms were ¥2,694 billion and ¥958 billion, respectively, at March 31, 2021, and ¥2,339 billion and ¥1,172 billion respectively, at March 31, 2022.

Repurchase agreements and secur

Repurchase agreements and securities lending transactions accounted for as secured borrowings	12 Months Ended
	Mar. 31, 2022
Repurchase agreements and securities lending transactions accounted for as secured borrowings	29. Repurchase agreements and securities lending transactions accounted for as secured borrowings The following table shows the gross amounts of liabilities associated with repurchase agreements and securities lending transactions, by remaining contractual maturity at March 31, 2021 and 2022: Overnight and continuous Up to 30 days 31-90 days Greater than 90 days Total (in billions of yen) 2021 Repurchase agreements 9,459 3,586 4,315 1,247 18,607 Securities lending transactions 943 15 — 250 1,208 Total 10,402 3,601 4,315 1,497 19,815 2022 Repurchase agreements 7,011 10,621 1,340 1,098 20,070 Securities lending transactions 1,098 74 — 189 1,361 Total 8,109 10,695 1,340 1,287 21,431 The following table shows the gross amounts of liabilities associated with repurchase agreements and securities lending transactions, by class of underlying collateral at March 31, 2021 and 2022: Repurchase agreements Securities lending transactions (in billions of yen) 2021 Japanese government bonds and Japanese local government bonds 1,787 352 Foreign government bonds and foreign agency mortgage-backed securities 15,917 131 Commercial paper and corporate bonds 284 57 Equity securities 544 654 Other 75 14 Total 18,607 1,208 2022 Japanese government bonds and Japanese local government bonds 1,714 217 Foreign government bonds and foreign agency mortgage-backed securities 17,445 90 Commercial paper and corporate bonds 271 52 Equity securities 609 989 Other 31 13 Total 20,070 1,361 The MHFG Group is required to post securities as collateral with a fair value equal to or in excess of the principal amount of the cash borrowed under repurchase agreements. For securities lending transactions, the Group receives collateral in the form of cash. These contracts involve risks, including (1) the counterparty may fail to return the securities at maturity and (2) the fair value of the securities posted may decline below the amount of the Group’s obligation and therefore the counterparty may require additional amounts. The Group attempts to mitigate these risks by entering into transactions mainly with central counterparty clearing houses which revalue assets and perform margin maintenance activities on a regular basis, diversifying the maturities and counterparties, and using mainly highly liquid securities.

Related Party Transactions

Related Party Transactions	12 Months Ended
	Mar. 31, 2022
Text Block [Abstract]
Related Party Transactions	30. Related party transactions The banking subsidiaries of MHFG make loans to the MHFG Group’s directors, executive officers, and other related parties. At March 31, 2021 and 2022, the aggregate loans to the Group’s equity method investees amounted to ¥550 billion and ¥604 billion, respectively, and outstanding loans to MHFG Group’s directors, executive officers, and other related parties were not considered significant. There were no loans to related parties that were considered nonaccrual. During the fiscal years ended March 31, 2021 and 2022, certain subsidiaries of MHFG partially withdrew assets from employee retirement benefit trusts, which were established for the payment of employees’ severance pay and retirement pensions. See Note 20 “Pension and other employee benefit plans” for further details. In addition, the other transactions with the related parties excluding loan transactions and partial withdrawal of assets from employee retirement benefit trusts, are considered immaterial. Summarized Financial Information of the MHFG Group’s Equity Method Investees Summarized financial information of the MHFG Group’s equity method investees as of March 31, 2021 and 2022, and for each of the three years ended March 31, 2022, is as follows: 2021 2022 (in billions of yen) Loans 7,521 7,765 Total assets 29,540 30,180 Deposits 10,301 8,713 Total liabilities 27,247 27,474 Total equity 2,293 2,706 Noncontrolling interests 13 14 2020 2021 2022 (in billions of yen) Total interest and dividend income 586 570 625 Total interest expense 198 188 182 Provision (credit) for credit losses 81 91 104 Net interest income after provision (credit) for credit losses 307 291 339 Income before income tax expense 196 237 332 Net income 150 178 246

Business segment information

Business segment information	12 Months Ended
	Mar. 31, 2022
Business segment information	31. Business segment information The MHFG Group consists of the following five in-house The services that each in-house Retail & Business Banking Company This company provides financial services for individual customers, small and medium-sized Corporate & Institutional Company This company provides financial services for large corporations, financial institutions and public corporations in Japan. Global Corporate Company This company provides financial services for Japanese overseas affiliated corporate customers and non-Japanese Global Markets Company This company invests in financial products with market risk, such as interest rate risk, equity risk, and credit risk. Asset Management Company This company develops financial products and provides financial services that match the asset management needs of its wide range of customers from individuals to institutional investors. The reportable segment information, set forth below, is derived from the internal management reporting systems used by management to measure the performance of the Group’s operating segments. Management measures the performance of each of the operating segments in accordance with internal managerial accounting rules and practices. In addition, the format and information are presented primarily on the basis of Japanese GAAP. Therefore, they are not consistent with the consolidated financial statements prepared in accordance with U.S. GAAP. A reconciliation is provided for the total amount of all business segments’ “Net business profits (losses) + Net gains (losses) related to ETFs and others” with income before income tax expense under U.S. GAAP, and the total amount of all business segments’ “Fixed assets” with the total amount of Premises and equipment-net, right-of-use MHFG (Consolidated) 2020 (1) Retail & Business Banking Company Corporate & Institutional Company Global Corporate Company Global Markets Company Asset Management Company Others (6) Total (in billions of yen) Gross profits + Net gains (losses) related to ETFs and others (2) 693.9 440.5 417.1 414.5 53.3 53.5 2,072.8 General and administrative expenses (3) 670.2 214.8 253.4 202.9 33.1 37.1 1,411.5 Equity in earnings (losses) of equity method investees—net 11.7 2.0 10.4 — 1.3 5.0 30.4 Amortization of goodwill and others 2.8 0.1 0.4 1.1 7.8 1.0 13.2 Others — — — — — (5.9 ) (5.9 ) Net business profits (losses) (4) 32.6 227.6 173.7 210.5 13.7 14.5 672.6 Fixed assets (5) 517.0 205.7 168.0 96.8 0.1 752.2 1,739.8 MHFG (Consolidated) 2021 (1) Retail & Business Banking Company Corporate & Institutional Company Global Corporate Company Global Markets Company Asset Management Company Others (6) Total (in billions of yen) Gross profits + Net gains (losses) related to ETFs and others (2) 697.7 472.8 456.0 490.3 50.8 33.2 2,200.8 General and administrative expenses (3) 639.6 206.5 259.1 217.7 33.0 52.8 1,408.7 Equity in earnings (losses) of equity method investees—net 5.5 3.9 10.9 — 1.1 (1.5 ) 19.9 Amortization of goodwill and others 2.3 0.1 0.4 0.8 7.6 1.0 12.2 Others — — — — — — — Net business profits (losses) (4) 61.3 270.1 207.4 271.8 11.3 (22.1 ) 799.8 Fixed assets (5) 543.9 193.5 169.1 98.4 — 750.8 1,755.7 MHFG (Consolidated) 2022 (1) Retail & Business Banking Company Corporate & Institutional Company Global Corporate Company Global Markets Company Asset Management Company Others (6) Total (in billions of yen) Gross profits + Net gains (losses) related to ETFs and others (2) 713.7 491.7 518.8 378.9 59.5 91.9 2,254.5 General and administrative expenses (3) 621.0 198.1 267.7 227.6 33.4 67.2 1,415.0 Equity in earnings (losses) of equity method investees—net 5.9 3.8 13.2 — 1.4 1.1 25.4 Amortization of goodwill and others 2.2 0.1 0.4 0.8 7.2 1.0 11.7 Others — — — — — — — Net business profits (losses) (4) 96.4 297.3 263.9 150.5 20.3 24.8 853.2 Fixed assets (5) 504.2 160.2 161.5 88.8 — 782.6 1,697.3 Notes: (1) Income and expenses of foreign branches of MHBK and foreign subsidiaries with functional currencies other than Japanese Yen have been translated for purposes of segment reporting using the budgeted foreign currency rates. Prior period comparative amounts for such foreign currency income and expenses have been translated using current period budgeted foreign currency rates. (2) “Gross profits + Net gains (losses) related to ETFs and others” is reported instead of sales reported by general corporations. Gross profits is defined as the sum of net interest income, fiduciary income, net fee and commission income, net trading income and net other operating income. Net gains (losses) related to ETFs and others consist of net gains (losses) on ETFs held by MHBK and MHTB on their non-consolidated (3) “General and administrative expenses” excludes non-allocated (4) Net business profits (losses) is used in Japan as a measure of the profitability of core banking operations, and is defined as gross profits (as defined above) less general and administrative expenses (excluding non-allocated (5) “Fixed assets” is presented based on Japanese GAAP and corresponds to the total amount of the following U.S. GAAP accounts: Premises and equipment-net; right-of-use (6) “Others” includes the following items: • profits and expenses pertaining to consolidated subsidiaries that are not subject to allocation; • consolidating adjustments, including elimination of internal transaction between each segment; • equity in earnings (losses) of equity method investees-net • profits and losses pertaining to derivative transactions that reflect the counterparty risk of the individual parties and other factors in determining fair market value. Reconciliation As explained above, the measurement bases of the internal management reporting systems and the income and expenses items included are different from the accompanying consolidated statements of income. Therefore, it is impracticable to present reconciliations of all the business segment’s information, other than net business profits (losses), to the corresponding items in the accompanying consolidated statements of income. A reconciliation of “Net business profits (losses) + Net gains (losses) related to ETFs and others” for the fiscal years ended March 31, 2020, 2021 and 2022 presented above to income before income tax expense shown on the consolidated statements of income and a reconciliation of “Fixed assets” at March 31, 2021 and 2022 to the total amount of Premises and equipment-net, right-of-use 2020 2021 2022 (in billions of yen) Net business profits (losses) + Net gains (losses) related to ETFs and others 672.6 799.8 853.2 Adjustment to reconcile management reporting to Japanese GAAP: General and administrative expenses: non-allocated 46.3 6.3 33.7 Expenses related to portfolio problems (including reversal of (provision for) general reserve for losses on loans) (183.3 ) (209.9 ) (255.9 ) Gains on reversal of reserves for possible losses on loans, and others 11.6 4.9 20.8 Net gains (losses) related to stocks—Net gains (losses) related to ETFs and others 126.6 10.1 (45.8 ) Net extraordinary gains (losses) (19.2 ) 115.9 44.0 Others (35.9 ) (74.9 ) (46.1 ) Income before income tax expense under Japanese GAAP 618.7 652.2 603.9 Adjustment to reconcile Japanese GAAP to U.S. GAAP: Derivative financial instruments and hedging activities 111.2 (86.4 ) (124.0 ) Investments (480.9 ) 523.5 (600.1 ) Loans (3.0 ) (16.9 ) (18.3 ) Allowances for credit losses (1) 0.7 83.3 51.5 Premises and equipment (96.1 ) (56.5 ) (68.5 ) Land revaluation 2.1 6.4 6.4 Business combinations 6.0 (1.0 ) 6.9 Pension liabilities (56.7 ) (153.2 ) (94.4 ) Consolidation of variable interest entities 39.3 104.6 42.3 Foreign currency translation 17.3 (31.5 ) (51.0 ) Others (5.1 ) 4.3 2.8 Income before income tax expense under U.S. GAAP 153.5 1,028.8 (242.5 ) 2020 2021 2022 (in billions of yen) Fixed assets 1,739.8 1,755.7 1,697.3 U.S. GAAP adjustments (2) 887.2 816.1 717.6 Premises and equipment-net, right-of-use 2,627.0 2,571.8 2,414.9 Notes: (1) The MHFG Group adopted ASU No.2016-13, 2019-04, 2019-05, 2019-11 off-balance-sheet (2) The U.S. GAAP adjustments are primarily comprised of GAAP differences mainly from right-of-use

Foreign activities

Foreign activities	12 Months Ended
	Mar. 31, 2022
Text Block [Abstract]
Foreign activities	32. Foreign activities The following table presents consolidated income statement and total assets information by major geographic area. Foreign activities are defined as business transactions that involve customers residing outside of Japan. However, as the MHFG Group’s operations are highly integrated globally, estimates and assumptions have been made for an allocation among the geographic areas. Americas Japan United States of America Others Europe Asia/Oceania excluding Japan, and others Total (in billions of yen) Fiscal year ended March 31, 2020: Total revenue (1) 1,681.0 801.5 95.1 270.4 610.9 3,458.9 Total expenses (2) 2,008.9 679.2 41.5 239.1 336.7 3,305.4 Income (loss) before income tax expense (benefit) (327.9 ) 122.3 53.6 31.3 274.2 153.5 Net income (loss) (312.8 ) 100.4 51.5 23.6 243.6 106.3 Total assets at end of fiscal year 137,470.4 34,650.4 4,137.3 15,487.0 19,473.7 211,218.8 Fiscal year ended March 31, 2021: Total revenue (1) 2,290.8 503.8 154.5 188.7 360.1 3,497.9 Total expenses (2) 1,918.2 243.5 14.4 115.8 177.2 2,469.1 Income before income tax expense 372.6 260.3 140.1 72.9 182.9 1,028.8 Net income 235.6 227.4 137.2 60.9 156.9 818.0 Total assets at end of fiscal year 152,613.7 31,939.9 4,405.3 14,150.6 18,542.0 221,651.5 Fiscal year ended March 31, 2022: Total revenue (1) 991.1 562.9 41.7 184.8 333.2 2,113.7 Total expenses (2) 1,713.8 265.0 19.0 189.2 169.2 2,356.2 Income (loss) before income tax expense (benefit) (722.7 ) 297.9 22.7 (4.4 ) 164.0 (242.5 ) Net income (loss) (509.0 ) 275.2 18.3 (16.3 ) 130.3 (101.5 ) Total assets at end of fiscal year 155,111.2 36,765.7 3,667.9 15,795.9 20,210.0 231,550.7 Notes: (1) Total revenue is comprised of Interest and dividend income and Noninterest income. (2) Total expenses are comprised of Interest expense, Provision (credit) for credit losses and Noninterest expenses.

Mizuho Financial Group, Inc., p

Mizuho Financial Group, Inc., parent company	12 Months Ended
	Mar. 31, 2022
Condensed Financial Information Disclosure [Abstract]
Mizuho Financial Group, Inc., parent company	33. Mizuho Financial Group, Inc., parent company The following tables present the parent company only financial information of MHFG: Condensed balance sheets 2021 2022 (in millions of yen) Assets: Cash and due from banking subsidiaries 44,619 51,356 Interest-bearing deposits in banking subsidiaries 347 414 Investments in subsidiaries and affiliated companies: Banking subsidiaries 8,561,350 8,102,149 Non-banking 1,241,783 878,776 Long-term loans receivable from subsidiaries: A banking subsidiary 7,851,894 7,942,367 A non-banking — 399,000 Other 549,068 648,946 Total 18,249,061 18,023,008 Liabilities and shareholders’ equity: Short-term borrowings from a banking subsidiary 850,000 755,000 Long-term debt 7,875,414 7,957,710 Other liabilities 418,409 396,086 Shareholders’ equity 9,105,238 8,914,212 Total 18,249,061 18,023,008 Condensed statements of income 2020 2021 2022 (in millions of yen) Income: Dividends from subsidiaries and affiliated companies: Banking subsidiaries 23,824 214,473 197,717 Non-banking 12,850 17,499 82,105 Management fees from subsidiaries 38,004 36,334 40,462 Interest income on loans and discounts 123,354 128,697 133,215 Gains on disposal of premises and equipment 10,866 — — Gains on sales of investments in subsidiaries — 40 53,005 Other income 7,088 11,970 11,319 Total 215,986 409,013 517,823 Expenses: Operating expenses 38,951 37,979 43,192 Interest expense 126,516 130,812 130,453 Losses on sales of investments in a subsidiary — — 26,606 Other expense 25,313 8,842 5,946 Total 190,780 177,633 206,197 Equity in undistributed net income (loss) of subsidiaries 130,930 341,369 (505,891 ) Income (loss) before income tax expense (benefit) 156,136 572,749 (194,265 ) Income tax expense (benefit) 5,941 (9,016 ) (89,543 ) Net income (loss ) 150,195 581,765 (104,722 ) Condensed statements of cash flows 2020 2021 2022 (in millions of yen) Cash flows from operating activities: Net income (loss) 150,195 581,765 (104,722 ) Adjustments and other (92,059 ) (390,748 ) 351,484 Net cash provided by operating activities 58,136 191,017 246,762 Cash flows from investing activities: Net change in loans (1,496,047 ) (1,167,385 ) (72,313 ) Purchases of premises and equipment (43,406 ) (41,382 ) (26 ) Proceeds from sales of premises and equipment 209,657 55,624 11 Proceeds from sales of investments in subsidiaries 245 125 452,500 Net change in other investing activities (5,395 ) (1,370 ) 223 Net cash provided by (used in) investing activities (1,334,946 ) (1,154,388 ) 380,395 Cash flows from financing activities: Net change in short-term borrowings (85,505 ) (10,000 ) (95,000 ) Proceeds from issuance of long-term debt 1,531,047 1,477,385 930,033 Repayment of long-term debt (35,000 ) (310,000 ) (1,256,720 ) Purchases of treasury stock (1,441 ) (1,849 ) (1,927 ) Dividends paid (190,386 ) (190,498 ) (196,783 ) Net change in other financing activities 962 65 44 Net cash provided by (used in) financing activities 1,219,677 965,103 (620,353 ) Net increase (decrease) in cash and cash equivalents (57,133 ) 1,732 6,804 Cash and cash equivalents at beginning of fiscal year 100,367 43,234 44,966 Cash and cash equivalents at end of fiscal year 43,234 44,966 51,770

Basis of presentation and sum_2

Basis of presentation and summary of significant accounting policies (Policies)	12 Months Ended
	Mar. 31, 2022
Basis of presentation	Basis of presentation Mizuho Financial Group, Inc. (“MHFG”) is a joint stock corporation with limited liability under the laws of Japan. MHFG is a holding company for Mizuho Bank, Ltd. (“MHBK”), Mizuho Trust & Banking Co., Ltd. (“MHTB”), Mizuho Securities Co., Ltd. (“MHSC”), Asset Management One Co., Ltd. (“Asset Management One”), and other subsidiaries. MHFG, through its subsidiaries (“the MHFG Group,” or “the Group”), provides domestic and international financial services in Japan and other countries. For a discussion of the Group’s segment information, see Note 31 “Business segment information.” MHFG and its domestic subsidiaries as well as its foreign subsidiaries maintain their accounting records in accordance with the accounting standards of Japan and those standards of the countries in which they are domiciled. Certain adjustments and reclassifications have been incorporated in the accompanying consolidated financial statements to conform them to the accounting principles generally accepted in the United States of America (“U.S. GAAP”). The consolidated financial statements are stated in Japanese yen, the currency of the country in which MHFG is incorporated and principally operates. The accompanying consolidated financial statements include the accounts of MHFG and its subsidiaries. MHFG’s fiscal year ends on March 31. MHFG’s subsidiaries fiscal year end is determined by each subsidiary. If the fiscal year end of a subsidiary has more than three months discrepancy from the MHFG’s fiscal year end, the subsidiary executes provisional financial closing. For those subsidiaries where the fiscal year end is not on March 31 and where the subsidiaries do not execute provisional financial close, the effect on the MHFG Group’s consolidated financial statements of all material events through the date of each of the periods presented in the consolidated financial statements has been considered for adjustment and/or disclosure. When determining whether to consolidate investee entities, the MHFG Group performs an analysis of the facts and circumstances of the particular relationships between the MHFG Group and the investee entities as well as the ownership of voting shares. The consolidated financial statements also include the accounts of VIEs for which MHFG or its subsidiaries have been determined to be the primary beneficiary in accordance with the Financial Accounting Standards Board (“FASB”) Accounting Standards Codification (“ASC”) 810, “Consolidation” (“ASC 810”). All significant intercompany transactions and balances have been eliminated upon consolidation. The MHFG Group accounts for investments in entities over which it has significant influence by using the equity method of accounting. These investments are included in Other investments and the Group’s proportionate share of income or loss is included in Equity in earnings (losses) of equity method investees—net. Certain comparative amounts for the prior period have been reclassified in order to conform to the current period’s presentation.
Use of estimates	Use of estimates The preparation of the consolidated financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect reported amounts and related disclosures. Specific areas, among others, requiring the application of management’s estimates and judgment include assumptions pertaining to the allowance for credit losses, valuation of deferred tax assets, valuation of derivative financial instruments, valuation of investments, valuation of certain long-term debt where the fair value option has been elected, valuation of pension and other employee benefits, and impairment of long-lived assets. During times of pandemics, such as COVID-19
Definition of cash and cash equivalents	Definition of cash and cash equivalents For purposes of the consolidated statements of cash flows, Cash and cash equivalents consists of Cash and due from banks and Interest-bearing deposits in other banks. Cash deposited with central banks that must be maintained to meet minimum regulatory requirements is classified as restricted cash and included in Cash and cash equivalents. See Note 8 “Pledged assets and collateral” for more information on restricted cash.
Translation of foreign currency financial statements and foreign currency transactions	Translation of foreign currency financial statements and foreign currency transactions Financial statements of overseas entities are prepared using the functional currency of each entity and translated into Japanese yen for consolidation purposes. Assets and liabilities are translated using the fiscal-year-end Foreign currency translation gains and losses related to the financial statements of overseas entities of the MHFG Group, net of related income tax effects, are credited or charged directly to Foreign currency translation adjustments, a component of Accumulated other comprehensive income (loss), net of tax (“AOCI”). The tax effects of gains and losses related to the foreign currency translation of financial statements of overseas entities are not recognized unless it is apparent that the temporary differences will reverse in the foreseeable future. Assets and liabilities of domestic and overseas entities denominated in foreign currencies are remeasured into the functional currency of the respective entity at the fiscal year-end
Call loans and call money	Call loans and call money Call loans and call money represent lending/borrowing, primarily through the Japanese short-term money market, to/from other financial institutions such as banks, insurance companies, and securities brokerage houses.
Repurchase and resale agreements, securities lending and borrowing and other secured financing transactions	Repurchase and resale agreements, securities lending and borrowing and other secured financing transactions Securities sold under agreements to repurchase (“repurchase agreements”), securities purchased under agreements to resell (“resale agreements”) and securities lending and borrowing transactions are accounted for as secured financing or lending transactions when control over the underlying securities is not deemed to be surrendered by the transferor. Otherwise, they are recorded as sales of securities with related forward repurchase commitments or purchases of securities with related forward resale commitments in accordance with ASC 860, “Transfers and Servicing” (“ASC 860”). Under resale agreements, securities borrowing and certain derivatives transactions, the MHFG Group receives collateral in the form of securities. In many cases, the MHFG Group is permitted to sell or repledge the securities obtained as collateral. Disclosures in respect of such collateral are presented in Note 8 “Pledged assets and collateral.” With respect to repurchase agreements, securities lending, and certain derivative transactions, counterparties may have the right to sell or repledge securities that the MHFG Group has pledged as collateral. The MHFG Group separately discloses these pledged securities in the consolidated balance sheets. The MHFG Group monitors credit exposure arising from resale agreements, repurchase agreements, securities borrowing and securities lending transactions on a regular basis, and additional collateral is obtained from or returned to counterparties, as appropriate.
Trading securities and trading securities sold, not yet purchased	Trading securities and trading securities sold, not yet purchased Trading securities consist of securities and money market instruments that are bought and held principally for the purpose of reselling in the near term with the objective of generating profits on short-term fluctuations in price. Trading securities sold, not yet purchased, are securities and money market instruments sold to third parties that the MHFG Group does not own and is obligated to purchase at a later date to cover the short position. Trading securities and trading securities sold, not yet purchased, are recorded on the trade date. Trading securities and trading securities sold, not yet purchased, are recorded at fair value in the consolidated balance sheets in Trading account assets and Trading account liabilities with realized and unrealized gains and losses recorded on a trade date basis in Trading account gains (losses)—net in the consolidated statements of income. Interest and dividends on trading securities, including securities sold, not yet purchased, are recorded in Interest and dividend income or Interest expense on an accrual basis.
Investments	Investments Debt securities that the MHFG Group has both the positive intent and ability to hold to maturity are classified as Held-to-maturity Available-for-sale At the end of each reporting period the MHFG Group performs a review to identify impaired available-for-sale available-for-sale first-in first-out Other investments include marketable and non-marketable non-marketable
Derivative financial instruments	Derivative financial instruments Derivative financial instruments are bought and held principally for the purpose of market making for customers, proprietary trading in order to generate trading revenues and fee income, and also to manage the MHFG Group’s exposure to interest rate, credit and market risks related to asset and liability management. Such derivative financial instruments include interest rate, foreign currency, equity, commodity and credit default swap agreements, options, caps and floors, and financial futures and forward contracts. Derivatives bought and held for trading purposes are recorded in the consolidated balance sheets at fair value in Trading account assets and Trading account liabilities. The fair values of derivatives in a gain position and a loss position are reported as Trading account assets and Trading account liabilities, respectively. Derivatives used for asset and liability management include contracts that qualify for hedge accounting under ASC 815, “Derivatives and Hedging” (“ASC 815”). To be eligible for hedge accounting, derivative instruments must be highly effective in achieving offsetting changes in fair values or variable cash flows of the hedged items attributable to the particular risk being hedged. All qualifying hedging derivatives are valued at fair value and included in Trading account assets or Trading account liabilities. Derivatives that do not qualify for hedge accounting under ASC 815 are treated as trading positions and are accounted for as such. The fair value amounts recognized for all derivatives are presented on a gross basis and not offset against the amounts recognized for the right to reclaim cash collateral or the obligation to return cash collateral under the master netting agreement with the same counterparty. The fair values of derivative financial instruments are determined based on quoted market prices or broker-dealer quotes, if available. If not available, the fair values are estimated using quoted market prices for similar instruments, option or binomial pricing models or a present value cash flow analysis, utilizing current observable market information, where available. In determining the fair values, the Group considers various factors such as exchange or over-the-counter Changes in the fair values of all derivatives are recorded in earnings, except for derivatives qualifying as net investment hedges under ASC 815 which are recorded in AOCI. The changes in the fair values of all derivatives relating to foreign currency exchange rates are included in Foreign exchange gains (losses)—net and Trading account gains (losses)—net. Other elements of the changes in the fair values, including interest rate, equity and credit related components, except these of certain credit derivatives hedging the credit risk in the corporate loan portfolio, are recognized in Trading account gains (losses)—net. The net gain (loss) resulting from changes in the fair values of certain credit derivatives where the Group purchases protection to mitigate its credit risk exposure related to its corporate loan portfolio is recorded in Other noninterest income (expenses). Certain financial and hybrid instruments often contain embedded derivative instruments that possess implicit or explicit contract terms similar to those of a derivative instrument. Such derivative instruments are required to be fair-valued separately from the host contracts if they meet the bifurcation criteria of an embedded derivative. Such criteria include that the entire instrument is not marked to market through earnings, the economic characteristics and risks of the embedded contract terms are not clearly and closely related to those of the host contract and the embedded contract terms would meet the definition of a derivative on a stand-alone basis.
Loans	Loans Loans are generally carried at the principal amount adjusted for unearned income and deferred net nonrefundable loan fees and costs. Loan origination fees, net of certain direct origination costs, are deferred and recognized over the contractual life of the loan as an adjustment of yield using a method that approximates the interest method. Interest income on performing loans is accrued and credited to income as it is earned. Unearned income and discounts or premiums on purchased loans are deferred and recognized over the life of the loan using a method that approximates the interest method. Loans are considered nonaccrual when, based on current information and events, it is probable that the MHFG Group will be unable to collect all the scheduled payments of principal and interest when due according to the contractual terms of the loans. Factors considered by management in determining if a loan is nonaccrual include delinquency status and the ability of the debtor to make payments of the principal and interest when due. Nonaccrual loans include loans past due for 90 days or more and restructured loans that meet the definition of a troubled debt restructuring (“TDR”) in accordance with ASC 310, “Receivables” (“ASC 310”). The majority of nonaccrual loans have no contractual delinquency due to interest reductions and/or postponement of principal and interest. In March 2020, the Coronavirus, Aid, Relief, and Economic Security Act (“the CARES Act”) was approved. The CARES Act and U.S. banking agencies had among other items, provided optional, temporary relief related to accounting for certain TDRs. The temporary TDR relief was available to banks for loan modifications related to obligors who were adversely impacted by COVID-19. In case loans are designated as nonaccrual loans, interest accruals and the amortization of net origination fees are suspended and capitalized interest is written off. Cash received on nonaccrual loans is accounted for as a reduction of the loan principal if the ultimate collectability of the principal amount is in doubt, otherwise, as interest income. Loans are not restored to accrual status until interest and principal payments are current and future payments are reasonably assured. Nonaccrual loans are restored to accrual loans and accrual status, when the MHFG Group determines that the borrower poses no concerns regarding current certainty of debt fulfillment. In general, such determination is made if the borrower qualifies for an obligor rating of E2 or above and is not classified as a special attention obligor. With respect to loans restructured in a TDR, in general, such loans are restored to accrual loans, and accrual status, when the borrower qualifies for an obligor rating of D or above. See Note 4 “Loans” for the definitions of obligor ratings. Loans that have been identified for sale are classified as loans held for sale within Other assets and are accounted for at the lower of cost or fair value on an individual loan basis. If management decides to retain certain loans held for sale for the foreseeable future or until maturity or payoff, such items are transferred to Loans at the lower of cost or fair value.
Financial instruments—current expected credit losses ("CECL")	Financial instruments—current expected credit losses (“CECL”) The adoption of this guidance established a single allowance framework for all financial assets measured at amortized cost and certain off-balance-sheet available-for-sale the fiscal
Allowance and provision (credit) for credit losses on loans	Allowance and provision (credit) for credit losses on loans Effective April 1, 2020, the allowance for credit losses on loans is established for current expected credit losses on the MHFG Group’s loan portfolio in accordance with ASC 326. Additionally, as of April 1, 2020, the Group did not elect the fair value option for financial assets measured at amortized cost basis. Prior to April 1, 2020, the allowance for credit losses on loans was established based on an incurred loss model in accordance with ASC 310 and ASC 450, “Contingencies” (“ASC 450”). The MHFG Group makes adjustments to the allowance for credit losses on loans through Provision (credit) for credit losses in the consolidated statements of income in each reporting period. Loan principal that management judges to be uncollectible, based on detailed loan reviews and a credit quality assessment, is charged off against the allowance for credit losses on loans. In general, the Group charges off loans when the Group determines that the obligor should be classified as substantially bankrupt or bankrupt. See Note 4 “Loans” for the definitions of obligor categories. Obligors in the retail portfolio segment are generally determined to be substantially bankrupt when they are past due for more than six months, and as for obligors in the corporate portfolio segment, the Group separately monitors the credit quality of each obligor without using time-based triggers. The MHFG Group maintains an appropriate allowance for credit losses on loans to represent management’s estimate of the expected credit losses in the Group’s loan portfolio. Management evaluates the appropriateness of the allowance for credit losses on loans semi-annually. The allowance considers expected credit losses over the remaining expected lives of the applicable instruments. The expected life of each instrument is determined by considering expected prepayments, contractual terms and cancellation features. The allowance for credit losses involves significant judgments on a number of matters including expectations of future economic conditions, assignment of obligor ratings, valuation of collateral, and the development of qualitative adjustments. When determining expected credit losses, a single forward-looking macroeconomic scenario is considered over a reasonable and supportable forecast period. This forward-looking macroeconomic scenario is in line with the scenario used for the Group’s business plan. If the scenario does not reflect a sudden change in economic conditions adequately, adjustments may be made to the scenario. After the forecast period, the Group reverts to long-term historical loss experience with a certain graduated transition period, to estimate losses over the remaining lives of financial assets measured at amortized cost and certain off-balance-sheet In terms of the internal risk ratings, for the corporate portfolio segment, the credit quality review process and the credit rating process serve as the basis for determining the allowance for credit losses on loans. Through such processes loans are categorized into groups to reflect the probability of default, whereby the MHFG Group’s management assesses the ability of borrowers to service their debt, taking into consideration current financial information, ability to generate cash, historical payment experience, analysis of relevant industry segments and current trends. For the retail portfolio segment, the different categories of past due status of loans are primarily utilized in the credit quality review and the credit rating processes as the basis for determining the allowance for credit losses on loans. In general, the MHFG Group estimates expected credit losses collectively on the loans in the case of normal and watch obligors, considering the risk associated with a particular pool and the probability that the exposures within the pool will deteriorate or default. The allowance for credit losses on nonaccrual loans includes the allowance for groups of loans which were collectively evaluated for expected credit losses, in addition to the allowance for those loans that were individually evaluated for expected credit losses. See Note 4 “Loans” for the definitions of obligor categories and classification of nonaccrual loans. The estimation of expected credit losses that are evaluated collectively begins with a quantitative calculation that considers the likelihood of the borrower changing delinquency status or moving from one obligor category or rating to another. The quantitative calculation covers expected credit losses over an instrument’s expected life and is estimated by applying credit loss factors to the MHFG Group’s estimated exposure at default. The credit loss factors incorporate the probability of default as well as the loss given default based on the historical loss rates. To supplement the historical loss data for overseas obligors, external credit ratings such as S&P are also used to calculate the probability of default. The model and inputs used to determine credit losses on loans that are evaluated collectively are analyzed on a periodic basis by comparing the estimated values with the actual results subsequent to the balance sheet date. The MHFG Group divides its overall portfolio into domestic and foreign portfolios and categorizes the domestic portfolio into four portfolio segments according to their risk profiles: corporate, retail, sovereign, and banks and financial institutions. The corporate portfolio segment consists of loans originated primarily by MHBK and MHTB, and includes mainly business loans such as those used for working capital and capital expenditure, as well as loans for which the primary source of repayment of the obligation is income generated by the relevant assets such as project finance, asset finance and real estate finance. The corporate portfolio segment is divided into two classes based on their risk characteristics: large companies, and small and medium-sized The retail portfolio segment consists mainly of residential mortgage loans originated by MHBK, and it is divided into two classes based on their risk characteristics: housing loan and others. For the retail portfolio segment, the Japanese unemployment rate is applied as a key factor. As it pertains to TDRs in the retail portfolio segment, the restructuring itself, as well as subsequent payment defaults, if any, are considered in determining obligor categories. Expected credit loss estimates also include consideration of expected cash recoveries on loans previously charged-off, The allowance recorded for individually evaluated loans is based on (1) the present value of expected future cash flows, after considering the restructuring effect and subsequent payment default with respect to TDRs, discounted at the loan’s initial effective interest rate, (2) the loan’s observable market price, or (3) the fair value of the collateral if the loan is collateral dependent. The collateral that the MHFG Group obtains for loans consists primarily of real estate. In obtaining the collateral, the Group evaluates the fair value of the collateral and its legal enforceability. The Group also performs subsequent re-evaluations The MHFG Group’s methodology for determining the appropriate allowance for credit losses on loans also considers the imprecision inherent in the methodologies used. As a result, the amounts determined under the methodologies described above could be adjusted by management to consider the potential impact of other qualitative factors which include, but are not limited to, imprecision in macroeconomic scenario assumptions and emerging risks related to changes in the environment that are affecting specific portfolio segments including segments impacted by the Russia-Ukraine situation. Considering internal and external factors affecting the credit quality of the portfolio, the Group incorporated the estimated impact of COVID-19 Russia-Ukraine In terms of the Russia-Ukraine situation, considering the country risk arising from the sanctions against Russia and the downgrading of their credit rating, as well as the risk of deterioration in the global economy due to inflation caused by soaring energy prices and the acceleration of supply chain disruptions caused by the withdrawal of operations from Russia, the MHFG Group incorporated an estimate of the Russia-Ukraine situation into the macroeconomic scenario used for determining the allowance for credit losses on loans.
Allowance and provision (credit) for credit losses on off-balance-sheet instruments	Allowance and provision (credit) for credit losses on off-balance-sheet The MHFG Group maintains an allowance for credit losses on off-balance-sheet off-balance-sheet off-balance-sheet
Allowance and provision (credit) for credit losses on available-for-sale securities	Allowance and provision (credit) for credit losses on available-for-sale The MHFG Group performs periodic reviews to identify impaired securities in accordance with ASC 326. Available-for-sale available-for-sale available-for-sale available-for-sale available-for-sale
Premises and equipment	Premises and equipment Premises and equipment are stated at historical cost, and depreciation and amortization are recorded over the estimated useful lives of the assets, except for leasehold improvements, which are amortized over the shorter of the estimated useful lives of the assets or the lease term. Depreciation and amortization are principally computed in accordance with the straight-line method with respect to buildings and leasehold improvements and in accordance with the declining-balance method with respect to other premises and equipment. The useful lives of premises and equipment are as follows: Years Buildings 3 to 50 Equipment and furniture 2 to 20 Regular repairs and maintenance costs that do not extend the estimated useful life of an asset are charged to expense as incurred. Upon sale or disposition of premises and equipment, the cost and related accumulated depreciation or amortization are removed from the accounts, and any gains or losses on disposal are included in Gains on disposal of premises and equipment or Occupancy expenses.
Impairment of long-lived assets	Impairment of long-lived assets The MHFG Group’s long-lived assets that are held for use are reviewed periodically for events or changes in circumstances that indicate possible impairment. The Group’s impairment review is based on an undiscounted cash flow analysis of a group of assets, combined with associated liabilities, at the lowest level for which identifiable cash flows exist. Impairment occurs when the carrying value of the asset group exceeds the future undiscounted cash flows that the asset group is expected to generate. When impairment is identified, the future cash flows are then discounted to determine the estimated fair value of the asset group and an impairment charge is recorded for the difference between the carrying value and the estimated fair value of the asset group. The long-lived assets to be disposed of by sale are carried at the lower of the carrying amount or fair value, less estimated cost to sell.
Software	Software Internal and external costs incurred in connection with developing and obtaining software for internal use during the application development stage are capitalized. Such costs include salaries and benefits for employees directly involved with and who devote time to the project, to the extent such time is incurred directly on the internal use software project. The capitalization of software ceases when the software project has been substantially completed. The capitalized software is amortized on a straight-line basis over the estimated useful life, generally 5 to 10 years. Internal use software is reviewed for impairment whenever events or changes in circumstances indicate that its carrying amount may not be recoverable.
Goodwill	Goodwill Goodwill represents the excess of the total fair value of the acquired company, which consists of the consideration transferred, the fair value of any interest in the acquiree already held by the acquirer and the fair value of any noncontrolling interest in the acquiree over the fair value of net identifiable assets acquired at the date of acquisition in a business combination. The MHFG Group accounts for goodwill in accordance with ASC 350, “Intangibles—Goodwill and Other” (“ASC 350”). Goodwill is recorded at a designated reporting unit level for the purpose of assessing impairment. Goodwill is not amortized but is tested for impairment at least annually or more often if events or circumstances indicate there may be impairment. For both the annual and interim tests, the Group has the option to either (a) perform a quantitative impairment test or (b) first perform a qualitative assessment to determine whether it is more likely than not that the fair value of a reporting unit is less than its carrying amount, in which case the Group would perform the quantitative test. An impairment loss is recorded to the extent the carrying amount of goodwill exceeds its estimated fair value. The estimated fair value of the reporting units is derived based on valuation techniques that the Group believes market participants would use for each of the reporting units. The Group generally determines the estimated fair value by utilizing a discounted cash flow methodology or methodologies that incorporate price-to-book
Intangible assets	Intangible assets Intangible assets having definite useful lives are amortized over their estimated useful lives on either a straight-line
Leases	Leases The MHFG Group, as a lessee, recognizes liabilities to make lease payments and right-of-use extend or terminate the lease that the Group is reasonably certain to exercise. The Group uses its incremental borrowing rates at the lease commencement to determine the lease liability, which is measured at the present value of future lease payments, when the rate implicit in the lease is not readily determinable. The Group has elected not to separate lease and non-lease right-of-use right-of-use right-of-use right-of-use
Pension and other employee benefits	Pension and other employee benefits MHFG and certain subsidiaries sponsor pension plans which provide defined benefits to retired employees and other postretirement benefit plans, including severance indemnities. Severance indemnities are amounts payable to eligible employees upon termination of employment and are payable as a lump sum. Periodic expense and accrued liabilities are computed based on the actuarial present value of benefits, net of investment returns expected from plan assets and their fair values at the balance sheet date. Net periodic expense is charged to Salaries and employee benefits. Net actuarial gains and losses that arise from differences between actual experience and assumptions are generally amortized over the average remaining service period of participating employees if they exceed the corridor, which is defined as the greater of 10% of plan assets or the projected benefit obligation.
Stock-based compensation	Stock-based compensation MHFG, MHBK, MHTB and MHSC have a responsibility-based stock compensation program for Directors (“Stock Compensation I”) and a performance-based stock compensation program for Directors (“Stock Compensation II”). MHFG and certain consolidated subsidiaries introduced both responsibility-based and performance-based stock compensation program for Operating Officers (“Stock Benefit”) in July 2021. For these programs, the stock-based compensation cost is determined based on the fair value of MHFG’s common stock as of grant date. The liability related to the cash-based compensation cost is remeasured at each reporting date based on the fair value of MHFG’s common stock. For Stock Compensation I, as the program is effectively vested on the grant date, the stock-based compensation cost is recognized on the grant date. For Stock Compensation II, the stock-based compensation costs are recognized evenly over the graded-vesting period, which is three years. For Stock Benefit, the stock-based compensation costs are recognized evenly over the vesting period, which is one year. See Note 21 “Stock-based compensation” for further details of the stock options and the stock compensation programs.
Long-term debt	Long-term debt Premiums, discounts and issuance costs of long-term debt are amortized based on a method that approximates the interest method over the respective terms of the long-term debt.
Obligations under guarantees	Obligations under guarantees The MHFG Group provides customers with a variety of guarantees and similar arrangements, including standby letters of credit, financial and performance guarantees, credit protection, and liquidity facilities. The MHFG Group recognizes guarantee fee income over the guarantee period. The MHFG Group receives such a guarantee fee at the inception of the guarantee or in installments and, in either case, the present value of the total fees approximates the fair value of the guarantee.
Fair Value Measurements	Fair Value Measurements The MHFG Group carries certain of its financial assets and liabilities at fair value on a recurring basis. These financial assets and liabilities are primarily composed of trading account assets, trading account liabilities, available-for-sale non-recurring Fair value is defined as the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. In accordance with ASC 820, “Fair Value Measurement” (“ASC 820”), the Group classifies its financial assets and liabilities into the fair value hierarchy (Level 1, 2, and 3). See Note 27 “Fair value” for the detailed definition of each level. When determining fair value, the MHFG Group considers the principal or most advantageous market in which the Group would transact and considers assumptions that market participants would use when pricing the asset or liability. The Group maximizes the use of observable inputs and minimizes the use of unobservable inputs when measuring fair value. See Note 27 “Fair value” for descriptions of valuation methodologies used for its assets and liabilities by product.
Fee and commission income	Fee and commission income The MHFG Group recognizes revenue from contracts with customers in an amount that reflects the consideration to which the Group expects to be entitled in exchange for transferring control of a promised service. The timing of revenue recognition is dependent on whether the Group satisfies a performance obligation by transferring control of the service to a customer over time or at a point in time. Fee and commission income is presented exclusive of consumption taxes. The major components of fee and commission income are as follows. Securities-related business fees mainly consist of brokerage fees and commissions, and asset-based revenues. Brokerage fees and commissions mainly include fees earned from the execution of customer transactions and sales commissions of stocks, bonds and investment trusts. Brokerage fees and commissions are recognized at the point in time on transaction date. Asset-based revenues mainly include fees received from investment trust management companies in return for administration services, such as record keeping services, of investment trusts. The amounts of asset-based revenues are calculated based on customer’s net asset value and recognized over time in the period when the related service is provided. Deposit-related fees include service charges on consumer and commercial deposit accounts such as account transfer charges. Deposit-related fees are recognized at the point in time when the transactions occur or the related service is provided. Lending-related fees include fees for lending business such as commitment fees and arrangement fees. Remittance business fees include service charges for domestic and international funds transfers and collections. These fees are recognized at the point in time when the related service is provided. Asset management business fees consist of investment trust management fees and investment advisory fees for investment trusts. These fees are received from investment trusts in return for asset management services and/or investment advisory services on behalf of customers. The amounts of these fees are calculated based on a percentage of customer’s net asset value. These fees are recognized over time in the period when the management and/or advisory service is provided and the amount is fixed. Trust-related business fees consist of trust fees earned primarily through fiduciary asset management and administrative service and other trust-related fees. Fees for fiduciary asset management and administration services for corporate pension plans and investment funds are recognized at the point on creation of the trust or completion date specified in the contract, or over time in the period when the related service is provided. Other trust-related fees mainly include brokerage commissions of real estate property, sales commissions of beneficial interest in real estate trust, consulting fees of real estate property and charges for stock transfer agent services. These fees are mainly earned on a transaction basis and recognized at the point in time when the related service is provided or over time in the period when the related service is provided. Agency business fees mainly include administration service fees related to the MHFG Group’s agency business such as Japan’s principal public lottery program and revenues from standing proxy services related to stocks and others. These fees are recognized at the point in time when the related service is provided or over time in the period when the related service is provided. Fees for other customer services include various revenues such as sales commissions of life insurance, service charges for electronic banking, financial advisory fees, and service charges for software development. Sales commissions from life insurance sales are received from insurance companies in return for selling insurance products and recognized when the insurance product is sold to customers. Service charges for electronic banking are mainly monthly basic usage fees and recognized over the related transaction period. Financial advisory fees are received as consideration for services supporting market research and business strategy planning, which are recognized over time in the period when the related advisory service based on the contract is rendered. Service charges for software development are recognized over time according to the progress of the development.
Fee and commission expenses	Fee and commission expenses The principal items included in fee and commission expenses are fee and commission expenses for remittance services and brokerages fees paid for securities transactions. These expenses are generally recognized on an incurred basis.
Income taxes	Income taxes Income taxes are accounted for in accordance with ASC 740, “Income Taxes” (“ASC 740”). Deferred income taxes reflect the net tax effects of (1) temporary differences between the carrying amounts of assets and liabilities for financial reporting purposes and the corresponding amounts used for income tax purposes, and (2) operating loss and tax credit carryforwards. A valuation allowance is recorded for any portion of the deferred tax assets unless it is more likely than not that the deferred tax assets will be realized. Deferred income tax benefit or expense is recognized for the changes in the net deferred tax asset or liability between periods.
Earnings per common share	Earnings per common share Basic earnings per common share are computed by dividing net income (loss) attributable to MHFG common shareholders by the weighted average number of common shares outstanding during the fiscal year. Diluted earnings per common share reflect all dilutive potential common shares such as stock options and the common shares of MHFG under the stock compensation programs. See Note 18 “Earnings per common share” for the computation of basic and diluted earnings per common share.

Basis of presentation and sum_3

Basis of presentation and summary of significant accounting policies (Tables)	12 Months Ended
	Mar. 31, 2022
Accounting Policies [Abstract]
Useful Lives of Premises and Equipment	The useful lives of premises and equipment are as follows: Years Buildings 3 to 50 Equipment and furniture 2 to 20

Investments (Tables)

Investments (Tables)	12 Months Ended
	Mar. 31, 2022
Amortized Cost, Gross Unrealized Gains and Losses, and Fair Value of Available-for-Sale and Held-to-Maturity Securities	The amortized cost, net of allowance for credit losses, gross unrealized gains and losses, and fair value of available-for-sale held-to-maturity Amortized (4)(5) Gross gains Gross losses Fair value ( in millions of yen 2021 Available-for-sale Debt securities: Japanese government bonds 20,953,200 1,945 34,562 20,920,583 Japanese local government bonds 463,673 544 658 463,559 U.S. Treasury bonds and federal agency securities 906,499 4,440 46 910,893 Other foreign government bonds 1,505,770 1,975 209 1,507,536 Agency mortgage-backed securities (1) 512,720 8,746 687 520,779 Residential mortgage-backed securities 70,111 761 188 70,684 Commercial mortgage-backed securities 709,938 6,196 39 716,095 Japanese corporate bonds and other debt securities 1,897,117 10,537 3,574 1,904,080 Foreign corporate bonds and other debt securities (2) 837,675 2,577 1,426 838,826 Total 27,856,703 37,721 41,389 27,853,035 Held-to-maturity Debt securities: Japanese government bonds 479,959 9,555 — 489,514 Agency mortgage-backed securities (3) 407,190 10,178 3,273 414,095 Total 887,149 19,733 3,273 903,609 Amortized (4)(5) Gross gains Gross losses Fair value ( in millions of yen 2022 Available-for-sale Debt securities: Japanese government bonds 25,191,315 5,794 38,379 25,158,730 Japanese local government bonds 421,557 254 2,165 419,646 U.S. Treasury bonds and federal agency securities 381,653 — 8,444 373,209 Other foreign government bonds 1,338,295 220 2,578 1,335,937 Agency mortgage-backed securities (1) 452,830 1,695 3,985 450,540 Residential mortgage-backed securities 58,246 194 312 58,128 Commercial mortgage-backed securities 848,568 5,437 214 853,791 Japanese corporate bonds and other debt securities 2,222,670 14,212 1,705 2,235,177 Foreign corporate bonds and other debt securities (2) 787,263 2,490 1,021 788,732 Total 31,702,397 30,296 58,803 31,673,890 Held-to-maturity Debt securities: Japanese government bonds 479,980 5,101 — 485,081 Agency mortgage-backed securities (3) 1,039,075 24 58,604 980,495 Total 1,519,055 5,125 58,604 1,465,576 Notes: (1) Agency mortgage-backed securities presented in this line consist of Japanese and Foreign agency mortgage-backed securities, of which the fair values were ¥520,746 million and ¥33 million, respectively, at March 31, 2021, and ¥450,507 million and ¥33 million, respectively, at March 31, 2022. All Japanese agency mortgage-backed securities are issued by Japan Housing Finance Agency, a Japanese government-sponsored enterprise. Foreign agency mortgage-backed securities primarily consist of Government National Mortgage Association (“Ginnie Mae”) securities, which are guaranteed by the United States government. (2) Other debt securities presented in this line primarily consist of Foreign negotiable certificates of deposit (“NCDs”) and asset-backed securities (“ABS”), of which the total fair values were ¥275,661 million at March 31, 2021, and ¥247,762 million at March 31, 2022. (3) All Agency mortgage-backed securities presented in this line are Ginnie Mae securities. (4) Amortized cost, net of the allowance for credit losses, of which the amounts related to available-for-sale (5) Accrued interest receivables are excluded from amortized cost, of which the amount were ¥10,379 million at March 31, 202 1
Amortized Cost and Fair Value of Available-for-Sale and Held-to-Maturity Securities by Contractual Maturity	The amortized cost, net of allowance for credit losses, and fair value of available-for-sale held-to-maturity Amortized cost Due in one year or less Due after one year through five years Due after five years through ten years Due after ten years Total (in millions of yen) Available-for-sale Debt securities: Japanese government bonds 19,242,514 4,160,143 1,681,312 107,346 25,191,315 Japanese local government bonds 27,258 220,168 166,619 7,512 421,557 U.S. Treasury bonds and federal agency securities 82,287 299,366 — — 381,653 Other foreign government bonds 1,066,461 269,579 1,129 1,126 1,338,295 Agency mortgage-backed securities — — — 452,830 452,830 Residential mortgage-backed securities — — — 58,246 58,246 Commercial mortgage-backed securities 30,000 444,413 374,155 — 848,568 Japanese corporate bonds and other debt securities 154,142 1,275,410 277,228 515,890 2,222,670 Foreign corporate bonds and other debt securities 452,173 186,434 130,201 18,455 787,263 Total 21,054,835 6,855,513 2,630,644 1,161,405 31,702,397 Held-to-maturity Debt securities: Japanese government bonds 100,023 379,957 — — 479,980 Agency mortgage-backed securities — — — 1,039,075 1,039,075 Total 100,023 379,957 — 1,039,075 1,519,055 Fair value Due in one year or less Due after one year through five years Due after five years through ten years Due after ten years Total (in millions of yen ) Available-for-sale Debt securities: Japanese government bonds 19,241,161 4,151,094 1,663,395 103,080 25,158,730 Japanese local government bonds 27,279 219,972 164,987 7,408 419,646 U.S. Treasury bonds and federal agency securities 81,742 291,467 — — 373,209 Other foreign government bonds 1,065,814 267,868 1,129 1,126 1,335,937 Agency mortgage-backed securities — — — 450,540 450,540 Residential mortgage-backed securities — — — 58,128 58,128 Commercial mortgage-backed securities 30,004 446,606 377,181 — 853,791 Japanese corporate bonds and other debt securities 154,196 1,276,212 278,697 526,072 2,235,177 Foreign corporate bonds and other debt securities 451,918 186,739 130,548 19,527 788,732 Total 21,052,114 6,839,958 2,615,937 1,165,881 31,673,890 Held-to-maturity Debt securities: Japanese government bonds 100,650 384,431 — — 485,081 Agency mortgage-backed securities — — — 980,495 980,495 Total 100,650 384,431 — 980,495 1,465,576
Gross Unrealized Losses and Fair Value of Available-for-Sale and Held-to-Maturity Securities, Aggregated by Length of Time that Individual Securities Have Been in a Continuous Unrealized Loss Position	The following table shows the gross unrealized losses, net of allowance for credit losses, and fair value of available-for-sale Less than 12 months 12 months or more Total Fair value Gross unrealized losses Fair value Gross unrealized losses Fair value Gross unrealized losses (in millions of yen) 2021 Available-for-sale Debt securities: Japanese government bonds 9,998,772 1,924 4,058,718 32,638 14,057,490 34,562 Japanese local government bonds 125,058 323 130,384 335 255,442 658 U.S. Treasury bonds and federal agency securities 38,625 46 — — 38,625 46 Other foreign government bonds 576,415 209 — — 576,415 209 Agency mortgage-backed securities (Note) 70,088 120 36,989 567 107,077 687 Residential mortgage-backed securities 9,270 52 11,435 136 20,705 188 Commercial mortgage-backed securities 12,530 6 10,351 33 22,881 39 Japanese corporate bonds and other debt securities 278,698 953 843,026 2,621 1,121,724 3,574 Foreign corporate bonds and other debt securities 233,405 1,426 — — 233,405 1,426 Total 11,342,861 5,059 5,090,903 36,330 16,433,764 41,389 2022 Available-for-sale Debt securities: Japanese government bonds 19,407,878 11,377 1,565,950 27,002 20,973,828 38,379 Japanese local government bonds 229,562 1,277 136,733 888 366,295 2,165 U.S. Treasury bonds and federal agency securities 321,073 7,209 41,555 1,235 362,628 8,444 Other foreign government bonds 729,134 2,178 71,647 400 800,781 2,578 Agency mortgage-backed securities (Note) 183,150 2,326 78,717 1,659 261,867 3,985 Residential mortgage-backed securities 9,221 11 17,193 301 26,414 312 Commercial mortgage-backed securities 58,815 185 13,939 29 72,754 214 Japanese corporate bonds and other debt securities 605,067 1,516 53,020 189 658,087 1,705 Foreign corporate bonds and other debt securities 302,569 692 53,338 329 355,907 1,021 Total 21,846,469 26,771 2,032,092 32,032 23,878,561 58,803 Note: Agency mortgage-backed securities presented in this line consist of Japanese agency mortgage-backed securities, of which the fair values were ¥107,077 million at March 31, 2021, and ¥261,867 million at March 31, 2022. All Japanese agency mortgage-backed securities are issued by Japan Housing Finance Agency, a Japanese government-sponsored enterprise.
Realized Gains and Losses on Sales of Available-for-Sale Securities	The following table shows the realized gains and losses on sales of available-for-sale 2020 2021 2022 (in millions of yen) Gross realized gains 41,903 3,309 12,540 Gross realized losses (13,398 ) (24,407 ) (40,077 ) Net realized gains (losses) on sales of available-for-sale 28,505 (21,098 ) (27,537 )
Summary of Details of Net Gains and Losses on Equity Securities	The following table shows the details of the net gains and losses on Equity securities for the fiscal years ended March 31, 2020, 2021 and 2022: 2020 2021 2022 (in millions of yen) Net gains (losses) recognized during the period on equity securities (557,391 ) 850,567 (60,563 ) Less: Net gains (losses) recognized during the period on equity securities sold during the period 1,710 82,969 17,000 Unrealized gains (losses) recognized during the reporting period on equity securities still held at the reporting period (559,101 ) 767,598 (77,563 )
Summary of Downward Adjustments and Impairments and Upward Adjustments	The following table shows carrying amounts of equity securities without readily determinable fair values, for which the measurement alternative is used, and cumulative amounts due to downward adjustments and impairments and upward adjustments, at March 31, 2020, 2021 and 2022: 2020 2021 2022 (in millions of yen) Carrying amounts at the end of the period 419,775 186,146 207,407 Downward adjustments and impairments 2,435 5,087 6,519 Upward adjustments 9,128 9,216 11,623
Summary of Composition of Other Investments	The following table summarizes the composition of Other investments at March 31, 2021 and 2022: 2021 2022 (in millions of yen) Equity method investments 460,025 519,552 Investments held by consolidated investment companies and other 55,321 62,836 Total 515,346 582,388
Summary of Equity Securities Without Readily Determinable Fair Values	The following table shows amounts recognized in earnings during the period due to downward adjustments and impairments and upward adjustments for equity securities without readily determinable fair values. 2020 2021 2022 (in millions of yen) Downward adjustments and impairments 1,272 3,084 2,626 Upward adjustments 6,928 404 2,459

Loans (Tables)

Loans (Tables)	12 Months Ended
	Mar. 31, 2022
Credit Quality Information of Loans Based on MHFG Group's Internal Rating System	The table below pres e Term loans by origination year 2020 2019 2018 2017 2016 Prior to Revolving Loans Total (in millions of yen) 2021 Domestic: Corporate: Large companies: Normal obligors 14,351,596 6,173,182 6,884,219 2,384,565 2,105,541 2,256,613 6,819,851 40,975,567 Watch obligors excluding special attention obligors 151,406 86,390 86,199 61,785 40,907 35,681 128,363 590,731 Nonaccrual loans 219,111 196,945 38,490 129,066 28,650 9,547 194,607 816,416 Small and medium-sized Normal obligors 633,438 463,744 397,656 224,791 205,687 502,707 518,612 2,946,635 Watch obligors excluding special attention obligors 62,300 24,245 30,007 13,547 13,536 24,430 29,041 197,106 Nonaccrual loans 78,238 10,794 7,341 5,168 3,154 8,852 28,853 142,400 Retail: Housing Loan: Normal obligors 785,194 588,599 588,535 600,179 741,969 4,599,546 — 7,904,022 Watch obligors excluding special attention obligors 2,041 1,075 1,566 1,343 2,127 39,046 — 47,198 Nonaccrual loans 20,706 2,268 1,399 1,421 1,640 35,135 — 62,569 Others: Normal obligors 431,277 154,675 127,379 88,649 85,042 317,237 526,703 1,730,962 Watch obligors excluding special attention obligors 50,212 14,288 10,450 5,888 3,713 5,796 10,545 100,892 Nonaccrual loans 32,594 2,086 1,145 901 837 8,780 12,557 58,900 Sovereign: Normal obligors 1,466,468 80,260 128,702 71,943 75,389 389,777 12,615 2,225,154 Watch obligors excluding special attention obligors 4,312 3,594 2,164 635 31 — — 10,736 Nonaccrual loans — — — — — — — — Banks and other financial institutions : Normal obligors 51,874 135,135 241,418 24,097 84,244 60,281 162,622 759,671 Watch obligors excluding special attention obligors — — — — — — — — Nonaccrual loans — — — — — — — — Total domestic 18,340,767 7,937,280 8,546,670 3,613,978 3,392,467 8,293,428 8,444,369 58,568,959 Foreign: Corporate (4) : Normal obligors 12,813,813 4,614,310 2,558,432 922,526 655,823 1,143,658 4,501,155 27,209,717 Watch obligors excluding special attention obligors 196,054 36,915 72,529 54,514 894 25,009 127,553 513,468 Nonaccrual loans 61,657 29,657 12,547 3,034 4,417 17,394 14,580 143,286 Retail: Normal obligors 2,100 2,342 1,468 1,034 1,074 1,401 18 9,437 Watch obligors excluding special attention obligors — — — 14 — 13 — 27 Nonaccrual loans — — — — — — — — Sovereign: Normal obligors 96,177 78,727 26,569 157,256 — 4,474 69,320 432,523 Watch obligors excluding special attention obligors — — — — — 20,118 — 20,118 Nonaccrual loans — 710 — — — — — 710 Banks and other financial institutions : Normal obligors 1,030,080 317,635 275,695 18,272 1,497 3,105 25,145 1,671,429 Watch obligors excluding special attention obligors 6,341 — 78 — 4,774 — — 11,193 Nonaccrual loans — — — — — — — — Total foreign 14,206,222 5,080,296 2,947,318 1,156,650 668,479 1,215,172 4,737,771 30,011,908 Total 32,546,989 13,017,576 11,493,988 4,770,628 4,060,946 9,508,600 13,182,140 88,580,867 Term loans by origination year 2021 2020 2019 2018 2017 Prior to Revolving Loans Total (in millions of yen) 2022 Domestic: Corporate: Large companies: Normal obligors 12,236,438 6,640,211 5,049,408 4,535,083 1,678,591 3,378,926 7,155,041 40,673,698 Watch obligors excluding special attention obligors 145,167 69,404 71,937 66,122 40,205 50,499 127,319 570,653 Nonaccrual loans 60,525 100,975 201,375 44,919 135,777 77,602 178,416 799,589 Small and medium-sized Normal obligors 540,315 396,611 376,056 283,061 170,952 494,420 547,726 2,809,141 Watch obligors excluding special attention obligors 44,488 31,196 29,597 31,919 12,231 32,511 25,277 207,219 Nonaccrual loans 17,866 20,110 14,434 10,817 7,081 38,171 32,081 140,560 Retail: Housing Loan: Normal obligors 798,354 544,246 518,662 526,828 543,893 4,752,430 — 7,684,413 Watch obligors excluding special attention obligors 1,512 1,485 1,510 1,939 1,226 40,243 — 47,915 Nonaccrual loans 12,510 3,132 802 1,180 970 30,598 — 49,192 Others: Normal obligors 195,545 277,015 111,702 90,880 60,919 315,375 497,173 1,548,609 Watch obligors excluding special attention obligors 23,586 34,974 10,177 7,995 4,122 6,388 9,491 96,733 Nonaccrual loans 6,932 7,862 3,157 4,253 4,076 22,951 12,602 61,833 Sovereign: Normal obligors 938,534 105,966 89,385 108,664 54,580 351,876 1,864 1,650,869 Watch obligors excluding special attention obligors 3,933 4,205 859 366 113 — — 9,476 Nonaccrual loans — — — — — — — — Banks and other financial institutions : Normal obligors 45,825 23,757 131,932 211,445 3 143,717 125,078 681,757 Watch obligors excluding special attention obligors — — — — — — — — Nonaccrual loans — — — — — — — — Total dom e 15,071,530 8,261,149 6,610,993 5,925,471 2,714,739 9,735,707 8,712,068 57,031,657 Foreign: Corporate (4) : Normal obligors 14,087,409 3,571,416 3,236,191 1,392,231 550,082 1,228,924 5,906,045 29,972,298 Watch obligors excluding special attention obligors 316,387 179,555 73,656 55,876 28,325 25,384 122,410 801,593 Nonaccrual loans 35,801 1,622 13,743 17,181 14,743 22,639 9,745 115,474 Retail: Normal obligors 2,403 1,774 1,858 1,013 532 3,089 15 10,684 Watch obligors excluding special attention obligors — — 37 — — 13 — 50 Nonaccrual loans — — — — — — — — Sovereign: Normal obligors 278,373 6,856 33,225 15,194 174,298 3,079 74,923 585,948 Watch obligors excluding special attention obligors — — — — — — — — Nonaccrual loans — — 643 — — — — 643 Banks and other financial institutions : Normal obligors 1,003,709 254,232 150,505 224,571 12,041 709 120,088 1,765,855 Watch obligors excluding special attention obligors 5,544 — — — — — — 5,544 Nonaccrual loans 837 — — — — — — 837 Total foreign 15,730,463 4,015,455 3,509,858 1,706,066 780,021 1,283,837 6,233,226 33,258,926 Tota l 30,801,993 12,276,604 10,120,851 7,631,537 3,494,760 11,019,544 14,945,294 90,290,583 Notes: (1) Special attention obligors are watch obligors with debt in TDR or 90 days or more delinquent debt. Loans to such obligors are considered nonaccrual. (2) The primary component of the retail portfolio segment is housing loans to individuals which obligor category is classified based on past due status. The trigger to reclassify obligors from normal obligors to watch obligors excluding special attention obligors is when the past due status is more than 30 days. (3) There were no significant revolving line of credit arrangements that converted to term loans during the fiscal year ended March 31, 2021 and (4) Corporate of foreign includes ¥221,908 million and ¥216,463
Impaired Loans Information	The table below presents nonaccrual loans information at March 31, 2021 and 2022: Amortized cost Interest income recognized Nonaccrual loans with an allowance Nonaccrual loans without an allowance Total nonaccrual loans (in millions of yen) 2021 Domestic: Corporate: Large companies 800,329 16,087 816,416 13,050 Small and medium-sized 121,031 21,369 142,400 1,759 Retail: Housing Loan 37,006 25,563 62,569 1,073 Others 37,884 21,016 58,900 806 Total domestic 996,250 84,035 1,080,285 16,688 Foreign: Total foreign 117,300 26,696 143,996 2,422 Total 1,113,550 110,731 1,224,281 19,110 2022 Domestic: Corporate: Large companies 783,305 16,284 799,589 9,426 Small and medium-sized 121,598 18,962 140,560 1,700 Retail: Housing Loan 26,812 22,380 49,192 946 Others 40,155 21,678 61,833 819 Total domestic 971,870 79,304 1,051,174 12,891 Foreign: Total foreign 110,284 6,670 116,954 1,469 Total 1,082,154 85,974 1,168,128 14,360 Notes: (1) Amounts represent the outstanding balances of nonaccrual loans. The MHFG Group’s policy for placing loans in nonaccrual status corresponds to the Group’s definition of nonaccrual loans. (2) Amounts represent the amount of interest income on nonaccrual loans recognized on a cash basis and included in Interest income on loans in the consolidated statements of income. (3) The majority of total foreign consist of corporate.
Troubled Debt Restructurings Entered Modified Periods by Type of Concession Granted	The following table presents modified loans that were determined to be TDRs during the fiscal years ended March 31, 2021 and 2022: Loan forgiveness or debt to equity swaps Interest rate reduction and/or postponement of principal and/or interest Recorded investment (1) Charge-offs (in millions of yen) 2021 Domestic: Corpora t Large companies — 160 597,281 Small and medium-sized — — 120,798 Retail: Housing Loan — — 21,548 Others — — 20,604 Banks and other financial institutions — — 3,200 Total domestic — 160 763,431 Foreign: Total foreign 2,614 4,385 163,149 Total 2,614 4,545 926,580 2022 Domestic: Corporate: Large companies 5,849 22,757 612,569 Small and medium-sized — — 125,103 Retail: Housing Loan — — 7,897 Others — — 21,749 Total domestic 5,849 22,757 767,318 Foreign: Total foreign — — 62,651 Total 5,849 22,757 829,969 Notes: (1) Amounts represent the book values of loans immediately after the restructurings. (2) The majority of total foreign consist of corporate.
Payment Defaults Occurred During Periods with Respect to Loans Modified as Troubled Debt Restructurings within Previous Twelve Months	The following table presents payment defaults which occurred during the fiscal years ended March 31, 2021 and 2022 with respect to the loans modified as TDRs within the previous twelve months: Recorded investment 2021 2022 (in millions of yen) Domestic: Corporate: Large companies 10,590 7,831 Small and medium-sized 5,603 2,777 Retail: Housing Loan 810 938 Others 2,133 1,000 Total domestic 19,136 12,546 Foreign: Total foreign 47,239 14,126 Total 66,375 26,672
Age Analysis of Past Due Loans	The table below presents an analysis of the age of the amortized cost basis in loans that are past due at March 31, 2021 and 2022: 30-59 days past due 60-89 days past due 90 days or more past due Total past due Current Total (in millions of yen) 2021 Domestic: Corporate: Large companies 1,275 4,607 27,387 33,269 42,349,445 42,382,714 Small and medium-sized 1,386 — 9,185 10,571 3,275,570 3,286,141 Retail: Housing Loan 9,776 7,102 21,257 38,135 7,975,654 8,013,789 Others 5,165 1,123 12,012 18,300 1,872,454 1,890,754 Sovereign — — — — 2,235,890 2,235,890 Banks and other financial institutions — — — — 759,671 759,671 Total domestic 17,602 12,832 69,841 100,275 58,468,684 58,568,959 Foreign: Total foreign — 7,477 30,795 38,272 29,973,636 30,011,908 Total 17,602 20,309 100,636 138,547 88,442,320 88,580,867 2022 Domestic: Corporate: Large companies 323 291 27,275 27,889 42,016,051 42,043,940 Small and medium-sized 693 641 10,370 11,704 3,145,216 3,156,920 Retail: Housing Loan 15,181 8,326 16,548 40,055 7,741,465 7,781,520 Others 4,454 1,068 11,009 16,531 1,690,644 1,707,175 Sovereign — — — — 1,660,345 1,660,345 Banks and other financial institutions — — — — 681,757 681,757 Total domestic 20,651 10,326 65,202 96,179 56,935,478 57,031,657 Foreign: Total foreign — — 28,816 28,816 33,230,110 33,258,926 Total 20,651 10,326 94,018 124,995 90,165,588 90,290,583 Note: The majority of total foreign consist of corporate.

Allowance for Credit Losses o_2

Allowance for Credit Losses on Loans (Tables)	12 Months Ended
	Mar. 31, 2022
Changes in Allowance for Loan Losses, Allowance for Loan Losses and Loans Outstanding Disaggregated on Basis of Impairment Method, by Portfolio Segment	Changes in Allowance for credit losses on loans by portfolio segment for the fiscal years ended March 31, 2020, 2021 and 2022 are shown below: Corporate Retail Total (in millions of yen) 2020 Balance at beginning of fiscal year 277,955 29,246 307,201 Provision (credit) for credit losses on loans 149,915 6,285 156,200 Charge-offs (35,021 ) (9,337 ) (44,358 ) Recoveries 26,338 1,578 27,916 Net charge-offs (8,683 ) (7,759 ) (16,442 ) Others (Note) (6,161 ) 57 (6,104 ) Balance at end of fiscal year 413,026 27,829 440,855 2021 Balance at beginning of fiscal year 413,026 27,829 440,855 April 1, 2020 adoption of CECL 77,514 78,241 155,755 Adjusted Balance at beginning of period 490,540 106,070 596,610 Provision (credit) for credit losses on loans 124,086 (11,310 ) 112,776 Charge-offs (72,212 ) (6,589 ) (78,801 ) Recoveries 13,047 888 13,935 Net charge-offs (59,165 ) (5,701 ) (64,866 ) Others (Note) 7,009 (680 ) 6,329 Balance at end of fiscal year 562,470 88,379 650,849 2022 Balance at beginning of fiscal year 562,470 88,379 650,849 Provision (credit) for credit losses on loans 194,022 (6,423 ) 187,599 Charge-offs (55,662 ) (4,178 ) (59,840 ) Recoveries 17,912 842 18,754 Net charge-offs (37,750 ) (3,336 ) (41,086 ) Others (Note) 12,500 (45 ) 12,455 Balance at end of fiscal year 731,242 78,575 809,817 Note: Others includes primarily foreign exchange translation.

Premises and equipment (Tables)

Premises and equipment (Tables)	12 Months Ended
	Mar. 31, 2022
Property, Plant and Equipment [Abstract]
Summary of Premises and Equipment	Premises and equipment at March 31, 2021 and 2022 consist of the following: 2021 2022 (in millions of yen) Land 569,337 571,837 Buildings 737,144 737,440 Equipment and furniture 414,201 373,825 Leasehold improvements 222,296 208,820 Construction in progress 23,441 21,737 Software 1,372,364 1,373,035 Total 3,338,783 3,286,694 Less: Accumulated depreciation and amortization 1,527,325 1,582,627 Premises and equipment—net 1,811,458 1,704,067

Goodwill and intangible assets

Goodwill and intangible assets (Tables)	12 Months Ended
	Mar. 31, 2022
Changes in Goodwill	The changes in Goodwill during the fiscal years ended March 31, 2020, 2021 and 2022 are as follows: 2020 2021 2022 (in millions of yen) Balance at beginning of fiscal year 95,151 92,997 92,695 Impairment losses recognized (2,155 ) (302 ) — Foreign exchange translation 1 — — Balance at end of fiscal year 92,997 92,695 92,695 Gross amount of goodwill (Note) 169,313 167,552 161,993 Accumulated impairment losses 76,316 74,857 69,298 Note: Goodwill is recorded at a designated reporting unit level for the purpose of assessing impairment. Goodwill is not allocated to the reportable segments in Note 31 “Business segment information.”
Gross Carrying Amount, Accumulated Amortization and Net Carrying Amount of Intangible Assets	The table below presents the gross carrying amount, accumulated amortization and net carrying amount of intangible assets, at March 31, 2021 and 2022: 2021 2022 Gross carrying amount Accumulated amortization Net carrying amount Gross carrying amount Accumulated amortization Net carrying amount (in millions of yen) Intangible assets subject to amortization: Customer relationships (Note) 126,979 79,362 47,617 126,979 87,277 39,702 Other 1,429 1,234 195 1,468 1,237 231 Total 128,408 80,596 47,812 128,447 88,514 39,933 Intangible assets not subject to amortization: Total 8,309 — 8,309 8,006 — 8,006 Total 136,717 80,596 56,121 136,453 88,514 47,939 Note: Customer relationships were acquired in connection with the merger of MHSC and Shinko on May 7, 2009 and the integration among asset management companies on October 1, 2016. See Note 1 “Basis of presentation and summary of significant accounting policies” for further information.
Estimated Aggregate Amortization Expense in Respect of Intangible Assets	The table below presents the estimated aggregate amortization expense in respect of intangible assets for the next five years: (in millions of yen) Fiscal year ending March 31: 2023 7,174 2024 6,660 2025 6,149 2026 5,645 2027 5,138

Pledged assets and collateral (

Pledged assets and collateral (Tables)	12 Months Ended
	Mar. 31, 2022
Amounts Pledged as Collateral for Borrowings and for Other Purposes	The following amounts, by balance sheet classification, have been pledged as collateral for borrowings and for other purposes at March 31, 2021 and 2022: 2021 2022 (in billions of yen) Interest-bearing deposits in other banks 71 75 Trading account assets 7,424 5,426 Investments 5,573 8,091 Loans 10,417 9,056 Other assets 2,291 3,023 Total 25,776 25,671
Associated Liabilities Collateralized by Pledged Assets	The associated liabilities collateralized by the above assets at March 31, 2021 and 2022 are summarized below: 2021 2022 (in billions of yen) Deposits 764 910 Payables under repurchase agreements 6,334 5,864 Payables under securities lending transactions 1,185 645 Other short-term borrowings 6,272 5,113 Long-term debt 192 542 Total 14,747 13,074

Deposits (Tables)

Deposits (Tables)	12 Months Ended
	Mar. 31, 2022
Balance and Remaining Maturities of Time Deposits and Certificates of Deposit Issued by Domestic and Foreign Offices	The balance and remaining maturities of time deposits and certificates of deposit issued by domestic and foreign offices at March 31, 2022 are shown in the following table: Time deposits Certificates of deposit Total (in millions of yen) Domestic offices: Due in one year or less 15,082,821 10,224,412 25,307,233 Due after one year through two years 1,374,855 222,560 1,597,415 Due after two years through three years 1,106,825 — 1,106,825 Due after three years through four years 306,455 500 306,955 Due after four years through five years 281,141 — 281,141 Due after five years 188,260 — 188,260 Total 18,340,357 10,447,472 28,787,829 Foreign offices: Due in one year or less 18,439,713 6,065,429 24,505,142 Due after one year through two years 18,847 78,816 97,663 Due after two years through three years 25,388 277,214 302,602 Due after three years through four years 19,581 — 19,581 Due after four years through five years 1,359 — 1,359 Due after five years — — — Total 18,504,888 6,421,459 24,926,347 Total 36,845,245 16,868,931 53,714,176
Estimated amounts of uninsured time deposits and certificates of deposit issued by domestic and foreign offices	The aggregate estimated amounts of time deposits and certificates of deposit that meet or exceed insurance limit issued by domestic and foreign offices at March 31, 2021 and 2022 are shown in the following table: 2021 2022 (in billions of yen) Domestic offices: Time deposits 12,004 10,437 Certificates of deposit 10,599 10,448 Total 22,603 20,885 Foreign offices: Time deposits 14,987 18,505 Certificates of deposit 6,594 6,421 Total 21,581 24,926

Short-term borrowings and lon_2

Short-term borrowings and long-term debt (Tables)	12 Months Ended
	Mar. 31, 2022
Details of Other Short-Term Borrowings	Details of Other short-term borrowings at March 31, 2021 and 2022 are as follows: 2021 2022 (in millions of yen) Short-term notes issued by consolidated VIEs of asset-backed commercial paper programs (1) 32,546 46,668 Commercial paper and short-term notes issued by MHFG’s subsidiaries (1) (2) 2,528,568 2,266,360 Borrowings from the Bank of Japan 6,253,123 5,105,225 Other 271,675 148,518 Total 9,085,912 7,566,771 Notes: (1) Short-term notes are issued under the laws of Japan in the form of commercial paper. (2) The amounts of commercial paper and short-term notes issued by MHFG’s subsidiaries were ¥2,105,068
Long-Term Debt with Original Maturities of More than One Year	Long-term debt with original maturities of more than one year at March 31, 2021 and 2022 is comprised of the following: 2021 2022 (in millions of yen) Obligations 9,170 4,621 Loan participation borrowings 169,069 220,312 Senior borrowings and bonds 7,494,512 8,600,493 Subordinated borrowings and bonds 4,033,720 3,752,790 Total 11,706,471 12,578,216
Interest Rates and Maturities of Senior Borrowings and Bonds, and Subordinated Borrowings and Bonds	The following table presents the interest rates and maturities of senior borrowings and bonds, and subordinated borrowings and bonds: Interest rates (1) Maturities (2) 2021 2022 (%) (in millions of yen) Senior borrowings and bonds: fixed rate denominated in Japanese yen 0.00-6.20 Apr.2022 Jun.2051 547,133 1,032,194 fixed rate denominated in U.S. dollars 0.00-4.55 Apr.2022 Mar.2048 3,275,076 3,581,901 fixed rate denominated in other currencies 0.00-6.00 Apr.2022 May.2041 838,247 1,223,991 floating rate denominated in Japanese yen 0.00-52.70 Apr.2022 Sep.2081 584,606 582,430 floating rate denominated in U.S. dollars 0.00-54.20 Apr.2022 Dec.2061 2,035,844 2,001,616 floating rate denominated in other currencies 0.00-16.70 Apr.2022 Sep.2041 213,606 178,361 Total 7,494,512 8,600,493 Subordinated borrowings and bonds: fixed rate denominated in Japanese yen 0.39-4.26 Jun.2022 3,618,520 3,171,343 fixed rate denominated in U.S. dollars 2.56-4.70 Jul.2022 Sep.2031 415,200 581,447 Total 4,033,720 3,752,790 Total 11,528,232 12,353,283 Notes: (1) The interest rates disclosed reflect the range of contractual rates in effect at March 31, 2022. (2) Maturity information disclosed is the range of maturities at March 31, 2022. (3) None of the long-term debt issuances above are convertible to common stock. (4) Certain debt agreements permit the MHFG Group to redeem the related debt, in whole or in part, prior to maturity at the MHFG Group’s option on terms specified in the respective agreements.
Contractual Maturities of Long-Term Debt	The following is a summary of contractual maturities of long-term debt subsequent to March 31, 2022: (in millions of yen) Fiscal year ending March 31: 2023 1,776,915 2024 1,119,756 2025 1,600,277 2026 614,659 2027 1,450,956 2028 and thereafter 6,015,653 Total 12,578,216

Other assets and liabilities (T

Other assets and liabilities (Tables)	12 Months Ended
	Mar. 31, 2022
Details of Other Assets and Liabilities	The following table sets forth the details of other assets and liabilities at March 31, 2021 and 2022: 2021 2022 (in millions of yen) Other assets: Accounts receivable: Receivables from brokers, dealers and customers for securities transactions 2,339,902 3,049,874 Other 393,410 557,842 Collateral pledged: Collateral pledged for derivative transactions 1,088,847 1,549,483 Margins provided for futures contracts 297,496 466,531 Other 939,557 1,006,849 Prepaid pension cost 999,962 762,147 Right-of-use 611,533 570,171 Security deposits 104,915 91,766 Loans held for sale 29,834 156,639 Other 651,572 775,940 Total 7,457,028 8,987,242 Other liabilities: Accounts payable: Payables to brokers, dealers and customers for securities transactions 2,576,887 1,406,965 Other 403,501 494,538 Guaranteed trust principal (Note) 814,509 810,776 Lease liabilitie 636,541 593,339 Collateral accepted: Collateral accepted for derivative transactions 763,642 1,075,591 Margins accepted for futures contracts 555,760 327,883 Unearned income 120,521 113,181 Other 1,337,397 1,437,949 Total 7,208,758 6,260,222 Note: Guaranteed trust principal, included in All other liabilities in the disclosure about consolidated VIEs in the accompanying balance sheets, is a liability of certain consolidated trust arrangements that meet the definition of a VIE for which the MHFG Group provides guarantees for the repayment of principal. See Note 24 “Variable interest entities and securitizations” for further discussion of the guaranteed principal money trusts.

Preferred stock (Tables)

Preferred stock (Tables)	12 Months Ended
	Mar. 31, 2022
Preferred stock
Schedule of Stock by Class	The composition of preferred stock at March 31, 2020, 2021 and 2022 is as follows: 2020 2021 2022 Class of stock Authorized Issued Authorized Issued Authorized Issued (number of shares) Class XIV preferred stock 90,000,000 — 90,000,000 — 90,000,000 — Class XV preferred stock 90,000,000 — 90,000,000 — 90,000,000 — Class XVI preferred stock 150,000,000 — 150,000,000 — 150,000,000 —

Common stock (Tables)

Common stock (Tables)	12 Months Ended
	Mar. 31, 2022
Common Stock
Schedule of Stock by Class	The following table shows the changes in the number of issued shares of common stock during the fiscal years ended March 31, 2020, 2021 and 2022: 2020 2021 2022 (shares) Balance at beginning of fiscal year 2,539,249,894 2,539,249,894 2,539,249,894 Issuance of new shares of common stock due to exercise of stock acquisition rights — — — Balance at end of fiscal year 2,539,249,894 2,539,249,894 2,539,249,894

Accumulated other comprehensi_2

Accumulated other comprehensive income (loss), net of tax (Tables)	12 Months Ended
	Mar. 31, 2022
Changes in Each Component of AOCI	Changes in each component of AOCI for the fiscal years ended March 31, 2020, 2021 and 2022 are as follows: 2020 2021 2022 (in millions of yen) AOCI, balance at beginning of fiscal year, previously reported 164,021 (9,494 ) 318,114 Cumulative effect of change in accounting principles (1,052 ) — — AOCI, balance at beginning of fiscal year, adjusted 162,969 (9,494 ) 318,114 Net unrealized gains (losses) on available-for-sale Balance at beginning of fiscal year 22,019 (19,592 ) (8,173 ) Unrealized holding gains (losses) during year (22,566 ) (4,911 ) (35,922 ) Less: reclassification adjustments for losses (gains) included in net income (19,045 ) 16,330 19,049 Change during year (41,611 ) 11,419 (16,873 ) Balance at end of fiscal year (19,592 ) (8,173 ) (25,046 ) Foreign currency translation adjustments: Balance at beginning of fiscal year, previously reported (58,558 ) (109,872 ) (86,873 ) Cumulative effect of change in accounting principles (Note) (1,052 ) — — Balance at beginning of fiscal year, adjusted (59,610 ) (109,872 ) (86,873 ) Foreign currency translation adjustments during year (49,888 ) 22,704 181,722 Less: reclassification adjustments for losses (gains) included in net income (374 ) 295 (745 ) Change during year (50,262 ) 22,999 180,977 Balance at end of fiscal year (109,872 ) (86,873 ) 94,104 Defined benefit plan adjustments: Balance at beginning of fiscal year 196,446 69,455 397,153 Unrealized gains (losses) during year (122,219 ) 331,668 (22,825 ) Less: reclassification adjustments for losses (gains) included in net income (4,772 ) (3,970 ) (18,973 ) Change during year (126,991 ) 327,698 (41,798 ) Balance at end of fiscal year 69,455 397,153 355,355 Own credit risk adjustments : Balance at beginning of fiscal year 4,114 50,515 16,007 Unrealized gains (losses) during year 45,560 (30,345 ) (858 ) Less: reclassification adjustments for losses (gains) included in net income 841 (4,163 ) 550 Change during year 46,401 (34,508 ) (308 ) Balance at end of fiscal year 50,515 16,007 15,699 Total other comprehensive income (loss), net of tax attributable to MHFG shareholders (172,463 ) 327,608 121,998 AOCI, balance at end of fiscal year (9,494 ) 318,114 440,112 Note: The MHFG Group adopted ASU No.2017-12, No.2017-12”) No.2017-12
Amounts Reclassified Out of Accumulated Other Comprehensive Income into Net Income	The following table shows the amounts reclassified out of AOCI into net income during the fiscal year ended March 31, 2022: Before tax (1) Tax effect (2) Net of tax before allocation to noncontrolling interests Net of tax attributable to noncontrolling interests (2) Net of tax attributable to MHFG shareholders (in millions of yen) Amounts reclassified out of AOCI into net income: Affected line items in the consolidated statements of income: Net unrealized gains (losses) on available-for-sale (27,553 ) 8,504 (19,049 ) — (19,049 ) Investment gains (losses)—net Foreign currency translation adjustments 745 — 745 — 745 Investment gains (losses)—net Defined benefit plan adjustments 26,745 (7,748 ) 18,997 (24 ) 18,973 Salaries and employee benefits Own credit risk adjustments (885 ) 271 (614 ) 64 (550 ) Other noninterest income (expenses) Total (948 ) 1,027 79 40 119 Notes: (1) The financial statement line item in which the amounts in the before tax column are reported in the consolidated statements of income is listed to the right of the table. (2) The financial statement line items in which the amounts in the tax effect and the net of tax attributable to noncontrolling interest columns are reported in the consolidated statements of income are Income tax expens e (benefit) and Net income (loss), respectively.

Regulatory matters (Tables)

Regulatory matters (Tables)	12 Months Ended
	Mar. 31, 2022
Capital Requirements and Regulatory Adjustments Over Transitional Period	The capital requirements and regulatory adjustments are being phased in over a transitional period as follows (italicized percentages indicate those still in transition periods): March 2021 March 2022 March 2023 March 2024 Minimum Common Equity Tier 1 capital 4.5 % 4.5 % 4.5 % 4.5 % Minimum Tier 1 capital 6.0 % 6.0 % 6.0 % 6.0 % Minimum total capital 8.0 % 8.0 % 8.0 % 8.0 % Phase out of recognition of capital instruments that no longer qualify as capital 10.0 % 0.0 % — — Capital conservation buffer 2.5 % 2.5 % 2.5 % 2.5 % Countercyclical capital buffer (1) 0.01 % 0.01 % 0.01 % 0.01 % Additional loss absorbency requirements for G-SIBs D-SIBs (2) 1.0 % 1.0 % 1.0 % 1.0 % Minimum Leverage Ratio 3.0 % 3.0 % 3.5 % (3) 3.5 % (3) Notes: (1) Figures assume that the countercyclical capital buffer will continue to be 0.01% after March 2023. (2) Figures assume that the additional loss absorbency requirements applied to the Group as a G-SIB D-SIB (3) This figure includes a leverage ratio buffer required to be met at 50% of the additional loss absorbency requirements applied to the Group as a G-SIB
Capital Adequacy Ratios of MHFG, MHBK, and MHTB Calculated in Accordance with Japanese GAAP and Guidelines Established by Financial Services Agency	Capital adequacy ratios and leverage ratios of MHFG, MHBK, and MHTB as of March 31, 2021 and 2022 calculated in accordance with Japanese GAAP and the guidelines established by the Financial Services Agency are set forth in the following table: 2021 2022 Amount Ratio Amount Ratio (in billions of yen, except percentages) Consolidated: MHFG: Common Equity Tier 1 capital: Required (1) 5,405 8.01 5,184 8.01 Actual 7,850 11.63 8,067 12.46 Tier 1 capital: Required (1) 6,418 9.51 6,155 9.51 Actual 9,702 14.37 9,713 15.00 Total risk-based capital: Required (1) 7,767 11.51 7,450 11.51 Actual 11,385 16.87 11,351 17.53 Leverage Ratio (2) : Required 6,016 3.00 6,389 3.00 Actual 9,702 4.83 9,713 4.56 MHBK: Common Equity Tier 1 capital: Required 2,823 4.50 2,683 4.50 Actual 6,972 11.11 6,968 11.68 Tier 1 capital: Required 3,764 6.00 3,578 6.00 Actual 8,819 14.05 8,604 14.42 Total risk-based capital: Required 5,019 8.00 4,771 8.00 Actual 10,400 16.57 10,150 17.02 Leverage Ratio (2) : Required 5,660 3.00 5,971 3.00 Actual 8,819 4.67 8,604 4.32 MHTB: Common Equity Tier 1 capital: Required 82 4.50 79 4.50 Actual 527 28.94 442 25.18 Tier 1 capital: Required 109 6.00 105 6.00 Actual 527 28.94 442 25.18 Total risk-based capital: Required 146 8.00 140 8.00 Actual 527 28.94 442 25.18 Leverage Ratio (2) : Required 138 3.00 130 3.00 Actual 527 11.41 442 10.20 Non-consolidated: MHBK: Common Equity Tier 1 capital: Required 2,648 4.50 2,528 4.50 Actual 6,561 11.14 6,293 11.20 Tier 1 capital: Required 3,531 6.00 3,370 6.00 Actual 8,406 14.28 7,919 14.09 Total risk-based capital: Required 4,708 8.00 4,494 8.00 Actual 9,987 16.96 9,483 16.88 Leverage Ratio (2) : Required 5,343 3.00 5,570 3.00 Actual 8,406 4.72 7,919 4.26 2021 2022 Amount Ratio Amount Ratio (in billions of yen, except percentages) MHTB: Common Equity Tier 1 capital: Required 82 4.50 78 4.50 Actual 519 28.63 425 24.40 Tier 1 capital: Required 109 6.00 104 6.00 Actual 519 28.63 425 24.40 Total risk-based capital: Required 145 8.00 139 8.00 Actual 519 28.64 425 24.40 Leverage Ratio (2) : Required 135 3.00 126 3.00 Actual 519 11.51 425 10.09 Notes: (1) The required ratios disclosed above, at March 31, 2021 and 2022, include the capital conservation buffer of 2.5%, the countercyclical capital buffer of 0.01% and the additional loss absorbency requirements for G-SIBs D-SIBs (2) The required and actual amounts disclosed above at March 31, 2021 and March 31, 2022 exclude amounts of deposits to the Bank of Japan.

Earnings per common share (Tabl

Earnings per common share (Tables)	12 Months Ended
	Mar. 31, 2022
Computation of Basic and Diluted Earnings Per Common Share	The following table sets forth the computation of basic and diluted earnings per common share for the fiscal years ended March 31, 2020, 2021 and 2022: 2020 2021 2022 (in millions of yen) Net income (loss): Net income (loss) attributable to MHFG common shareholders 150,195 581,765 (104,722 ) Effect of dilutive securities — — — Net income (loss) attributable to common shareholders after assumed conversions 150,195 581,765 (104,722 ) 2020 2021 2022 (thousands of shares) Shares: Weighted average common shares outstanding 2,537,368 2,537,513 2,537,051 Effect of dilutive securities: Stock options and the common shares of MHFG under the stock compensation programs (Note) 158 89 — Weighted average common shares after assumed conversions 2,537,526 2,537,602 2,537,051 2020 2021 2022 (in yen) Earnings per common share: Basic net income (loss) per common share 59.19 229.27 (41.28 ) Diluted net income (loss) per common share (Note) 59.19 229.26 (41.28 ) Note: For the fiscal years ended March 31, 2020, 2021 and 2022, the performance-based plan under the stock compensation programs could potentially dilute earnings per common share but were not included in the computation of diluted earnings per common share due to their antidilutive effects. In addition, for the fiscal year ended March 31, 2022, the computation of diluted earnings per common share did not assume exercise of stock options, as the effect of such exercise would be antidilutive

Income taxes (Tables)

Income taxes (Tables)	12 Months Ended
	Mar. 31, 2022
Components of Income Tax Expense (Benefit)	The following table presents the components of Income tax expense (benefit) for the fiscal years ended March 31, 2020, 2021 and 2022: 2020 2021 2022 (in millions of yen) Current: Domestic 96,231 81,023 42,401 Foreign 52,885 78,992 71,947 Total current tax expense 149,116 160,015 114,348 Deferred: Domestic (111,341 ) 55,927 (256,093 ) Foreign 9,400 (5,226 ) 728 Total deferred tax expense (benefit) (101,941 ) 50,701 (255,365 ) Total income tax expense (benefit) 47,175 210,716 (141,017 )
Detailed Amounts of Tax Effects of Items Recorded Directly in Equity	The preceding table does not reflect the tax effects of items recorded directly in Equity for the fiscal years ended March 31, 2020, 2021 and 2022. The detailed amounts recorded directly in Equity are as follows: 2020 2021 2022 (in millions of yen) Net unrealized gains (losses) on available-for-sale Unrealized gains (losses) (10,012 ) (2,810 ) (16,489 ) Less: reclassification adjustments (8,410 ) 7,195 8,504 Total (18,422 ) 4,385 (7,985 ) Defined benefit plan adjustments: Unrealized gains (losses) (52,888 ) 143,653 (9,020 ) Less: reclassification adjustments (1,765 ) (1,424 ) (7,748 ) Total (54,653 ) 142,229 (16,768 ) Own credit risk adjustments: Unrealized gains (losses) 5,052 919 1,745 Less: reclassification adjustments 387 (1,911 ) 271 Total 5,439 (992 ) 2,016 Total tax effect before allocation to noncontrolling interests (67,636 ) 145,622 (22,737 )
Reconciliation of Income Tax Expense at Effective Statutory Tax Rate to Actual Income Tax Expense	The following table shows a reconciliation of Income tax expense at the effective statutory tax rate to the actual income tax expense for the fiscal years ended March 31, 2020, 2021 and 2022: 2020 2021 2022 (in millions of yen, except tax rates) Income (loss) (benefit) 153,490 1,028,764 (242,488 ) Effective statutory tax rate 30.62 % 30.62 % 30.62 % Income tax calculated at the statutory tax rate 46,999 315,007 (74,250 ) Income not subject to tax (7,758 ) (7,446 ) (10,219 ) Expenses not deductible for tax purposes 1,290 728 828 Tax rate differentials of subsidiaries (5,756 ) (9,252 ) (8,035 ) Change in valuation allowance 5,984 (39,410 ) 16,196 (Note) Noncontrolling interest income (loss) of consolidated VIEs 14,796 (70,143 ) 5,088 Effect of enacted change in tax rates (210 ) (213 ) (29 ) Reversal of outside basis differences — — (122,633 ) (Note) Foreign tax credit and payments 1,823 1,657 40,228 Income excluded from taxable income of enterprise ta x (4,040 ) (5,076 ) (6,944 ) Oth e r (5,953 ) 24,864 18,753 Income tax expense (benefi t ) 47,175 210,716 (141,017 ) Note: These amounts for the fiscal year ended March 31, 2022 mainly represent the reversal of an outside basis difference related to the share buyback conducted by MHSC in response to improving the capital position and aligning to the MHFG Group’s capital policy and the related increase in the valuation allowance.
Components of Net Deferred Tax Assets (Liabilities)	The components of n e 2021 2022 (in millions of yen) Deferred tax assets: Allowance for credit losses 247,983 292,277 Lease liabilities 195,629 183,537 Trading securities 8,519 118,242 Premises and equipment 64,389 65,051 Derivative financial instruments 14,893 52,321 Available-for-sale 1,164 8,313 Net operating loss carryforwards (1) 151,383 183,410 (2) Other 237,730 223,564 921,690 1,126,715 Valuation allowance (1) (129,150 ) (163,164 ) (2) Deferred tax assets, net of valuation allowance 792,540 963,551 Deferred tax liabilities: Prepaid pension cost and accrued pension liabilities 292,397 221,256 Investments 259,276 213,398 Right-of-use 188,902 176,591 Other 83,952 104,020 Deferred tax liabilities 824,527 715,265 Net deferred tax assets (liabilities) (31,987 ) 248,286 Notes: (1) The amount includes ¥85,001 million and ¥73,736 million related to MHSC’s net operating loss carryforwards resulting mainly from the organizational restructuring of certain foreign subsidiaries as of March 31, 20 2 (2) The amount includes ¥26,633 million related to MHFG’s net operating loss carryforwards resulting mainly from intercompany capital transactions in relation to the share buyback conducted by MHSC as of March 31, 2022. The tax effect of the net operating loss carryforwards is substantially offset by ¥24,675 million of valuation allowance as a result of considering all available evidence regarding sources of future taxable income including historical trends in taxable income in the preceding periods and forecasted taxable income.
Breakdown of Net Operating Loss Carryforwards by Tax Jurisdiction	The following table and accompanying footnotes provide a breakdown of deferred tax assets and the valuation allowance recognized in respect of net operating loss carryforwards by tax jurisdiction and by year of expiration as of March 31, 2021 and 2022: Deferred tax assets Valuation allowance Deferred tax assets, net of valuation allowance (in billions of yen) 2021 Japan (1) 94 (64 ) 30 The United States 2 — 2 The United Kingdom (2) 54 (54 ) — Others 1 — 1 Total 151 (118 ) 33 2022 Japan (3) 106 (77 ) 29 The United States 1 — 1 The United Kingdom (2) 75 (75 ) — Others 1 — 1 Total 183 (152 ) 31 Notes: (1) ¥85 billion of the Japan deferred tax assets of ¥94 billion is related to MHSC, which is substantially offset by a valuation allowance, and will expire during the fiscal year ending March 31, 2026. (2) The United Kingdom net operating loss carryforwards may be carried forward indefinitely for tax purposes. (3) ¥74 billion of the Japan deferred tax assets of ¥106 billion is related to MHSC, which is substantially offset by a valuation allowance, and will expire during the fiscal year ending March 31, 2026. ¥27 billion of the Japan deferred tax assets of ¥106 billion is related to MHFG, which is substantially offset by a valuation allowance, and will mostly
Roll-forward Valuation Allowance	The following table presents a roll-forward of the valuation allowance for the fiscal years ended March 31, 2020, 2021 and 2022: 2020 2021 2022 (in millions of yen) Balance at beginning of fiscal year 158,581 165,278 129,150 Changes that directly affected Income tax expense 5,984 (39,410 ) 16,196 Changes that did not affect Income tax expense: Expiration of net operating loss carryforwards — — — Others 713 3,282 17,818 Tota l 713 3,282 17,818 Balance at end of fiscal year 165,278 129,150 163,164
Net Operating Losses Carryforwards by Expiration Date	At March 31, 2022, the MHFG Group had net operating loss carryforwards totaling ¥589 billion. These carryforwards are scheduled to expire as follows: Net operating loss carryforwards (1) (in billions of yen) Fiscal year ending March 31: 2023 — 2024 — 2025 — 2026 246 2027 3 2028 and thereafter (2) 340 Total 589 Notes: (1) Net operating loss carryforwards related to Japanese local taxes recorded at MHFG in the fiscal year ended March 31, 2022 in the amount of ¥499 billion (tax effected ¥24 billion) are not included in the table. The net operating loss carryforwards is fully offset by valuation allowance and will expire during the fiscal year ending March 31, 2032. (2) Including the net operating loss carryforwards which may be carried forward indefinitely in the United Kingdom.
Roll-forward of Unrecognized Tax Benefits	The following table is a roll-forward of unrecognized tax benefits for the fiscal years ended March 31, 2020, 2021 and 2022: 2020 2021 2022 (in millions of yen) Total unrecognized tax benefits at beginning of fiscal year 12,323 3,374 4,401 Gross amount of increases (decreases) related to positions taken during prior years 199 455 (576 ) Gross amount of increases related to positions taken during the current year 328 524 954 Amount of decreases related to settlements (9,420 ) — — Foreign exchange translation (56 ) 48 466 Total unrecognized tax benefits at end of fiscal year 3,374 4,401 5,245

Pension and other employee be_2

Pension and other employee benefit plans (Tables)	12 Months Ended
	Mar. 31, 2022
Components of Net Periodic Benefit Cost of Severance Indemnities and Pension Plans	The following table presents the components of net periodic cost of the severance indemnities and pension plans for the fiscal years ended March 31, 2020, 2021 and 2022: 2020 2021 2022 (in millions of yen) Service cost-benefits earned during the fiscal year 45,697 39,672 33,190 Interest costs on projected benefit obligations 5,590 5,790 5,636 Expected return on plan assets (40,551 ) (41,887 ) (37,051 ) Amortization of prior service cost (benefits) 121 (2,378 ) (4,820 ) Amortization of net actuarial loss (gain) (5,873 ) 1,671 (20,485 ) Special termination benefits 9,793 9,569 10,791 Loss (gain) on settlement — (3,945 ) — Net periodic benefit cost 14,777 8,492 (12,739 )
Other Changes in Plan Assets and Benefit Obligations Recognized in Other Comprehensive Income (Loss) Before-Tax	Other changes in plan assets and benefit obligations recognized in other comprehensive income (loss) before-tax 2021 2022 (in millions of yen) Net actuarial gain (loss) 395,028 (36,796 ) Amortization of net actuarial loss (gain) 1,671 (20,485 ) Settlement loss (gain) of net actuarial loss (gain) (3,945 ) — Prior service benefits (cost) 74,160 (1 ) Amortization of prior service cost (benefits) (2,378 ) (4,820 ) Total recognized in other comprehensive income (loss) before-tax 464,536 (62,102 )
Weighted-Average Assumptions Used to Determine Benefit Obligations and Net Periodic Benefit Cost	Weighted-average assumptions used to determine benefit obligations and net periodic benefit cost are as follows: 2020 2021 2022 Weighted-average assumptions used to determine benefit obligations at fiscal year end: Discount rates 0.37 % 0.38 % 0.52 % Rates of increase in future compensation levels 1.80-4.80 % 1.80 % 2.00 % Interest credit rates 4.95 % 4.38 % 4.39 % Weighted-average assumptions used to determine net periodic benefit cost during the Discount rates 0.34 % 0.37 % 0.38 % Rates of increase in future compensation levels 1.80-4.80 % 1.80-4.80 % 1.80 % Expected rates of return on plan assets 1.68 % 1.79 % 1.54 % Interest credit rates 4.97 % 4.95 % 4.38 %
Combined Funded Status and Amounts Recognized in Accompanying Consolidated Balance Sheets	The following table sets forth the combined funded status and amounts recognized in the accompanying consolidated balance sheets at March 31, 2021 and 2022 for the plans of MHFG and its subsidiaries: 2021 2022 (in millions of yen) Change in benefit obligations: Benefit obligations at beginning of fiscal year 1,571,296 1,437,843 Service cost 39,672 33,190 Interest cost 5,790 5,636 Plan participants’ contributions 1,131 1,089 Amendments (1) (74,160 ) 1 Actuarial loss (gain) (6,938 ) (19,939 ) Foreign exchange translation 2,971 4,099 Benefits paid (52,930 ) (54,483 ) Lump-sum (27,357 ) (29,697 ) Settlement (2) (21,632 ) — Benefit obligations at end of fiscal year 1,437,843 1,377,739 Change in plan assets: Fair value of plan assets at beginning of fiscal year 2,252,624 2,412,745 Actual return (negative return) on plan assets 395,555 (8,008 ) Foreign exchange translation 3,570 3,863 Partial withdrawal of assets from employee retirement benefits trusts (3) (188,299 ) (270,172 ) Employer contributions 24,939 28,977 Plan participants’ contributions 1,131 1,089 Benefits paid (52,930 ) (54,483 ) Settlement (2) (23,845 ) — Fair value of plan assets at end of fiscal year 2,412,745 2,114,011 Funded status 974,902 736,272 Amounts recognized in the consolidated balance sheets consist of: Prepaid pension cost 999,962 762,147 Accrued pension liability (25,060 ) (25,875 ) Net amount recognized 974,902 736,272 Amounts recognized in Accumulated other comprehensive income (loss) before-tax Prior service benefits (cost) 67,856 63,030 Net actuarial gain (loss) 478,966 421,690 Net amount recognized 546,822 484,720 Notes: (1) The amount of ¥74,160 million for March 31, 2021 includes ¥73,998 million of prior service benefits recognized during the six months ended September 30, 2020 related to an amendment to the defined benefit pension plans at MHFG and certain domestic subsidiaries. In September 2020, based on various approvals, MHFG and certain domestic subsidiaries communicated to their employees the amendment to the defined benefit pension plans that was effective as of October 1, 2020. In accordance with ASC 715, “Compensation—Retirement Benefits” (“ASC 715”), any change in projected benefit obligations due to a plan amendment is required to be recognized as prior service benefits (cost) as of the amendment date. (2) The amount of ¥21,632 million and ¥23,845 million of settlement for March 31, 2021 resulted from partial transition from the defined benefit pension plans to the defined contribution pension plans, which occurred during the second half of the fiscal year ended March 31, 2021 at MHFG and certain domestic subsidiaries. This partial transition constitutes a settlement under ASC 715 and any gain or loss is required to be recognized in the consolidated results of operations once settlement criteria are met. The settlement criteria were met during the second half of the fiscal year ended March 31, 2021. (3) During the fiscal year ended March 31, 2021 and 2022, certain subsidiaries of MHFG partially withdrew assets from employee retirement benefit trusts, which were established for the payment of employees’ severance pay and retirement pensions. Overall, the trusts remain in overfunded status as of March 31, 2022. No gains or losses have been recognized as a result of this transaction.
Plans with Projected Benefit Obligations in Excess of Plan Assets and Plans with Accumulated Benefit Obligations in Excess of Plan Assets	The following table shows the projected benefit obligations and the fair value of plan assets for the plans of MHFG and its subsidiaries with projected benefit obligations in excess of plan assets, and the accumulated benefit obligations and the fair value of plan assets for the plans with accumulated benefit obligations in excess of plan assets at March 31, 2021 and 2022: 2021 2022 (in millions of yen) Plans with projected benefit obligations in excess of plan assets: Projected benefit obligations 49,110 31,829 Fair value of plan assets 24,050 5,954 Plans with accumulated benefit obligations in excess of plan assets: Accumulated benefit obligations 49,110 31,829 Fair value of plan assets 24,050 5,954 Note: The plans with projected benefit obligations in excess of plan assets include those with accumulated benefit obligations in excess of plan assets.
Target Allocation for Plan Assets Excluding those of Employee Retirement Benefit Trusts	MHFG and certain subsidiaries’ target allocation for the plan assets, excluding those of the employee retirement benefit trusts, at March 31, 2022 is as follows: Asset category Asset ratio Japanese equity securities 5.00 % Japanese debt securities 34.00 % Foreign equity securities 25.00 % Foreign debt securities 23.00 % General account of life insurance companies 11.00 % Other 2.00 % Total 100.00 % Note: General account of life insurance companies is a contract with life insurance companies which guarantees payments of principal and predetermined interest payments.
Fair Value of Plan Assets by Asset Category	The following table presents the fair value of plan assets of MHFG and its subsidiaries at March 31, 2021 and 2022, by asset class. For the detailed information on fair value measurements, including descriptions of Level 1, 2 and 3 of the fair value hierarchy and the valuation methodologies, see Note 27 “Fair value.” 2021 2022 Level 1 Level 2 Level 3 Total Level 1 Level 2 Level 3 Total (in billions of yen) Japanese equity securities: Common stocks (1) 1,291 — — 1,291 1,003 — — 1,003 Pooled funds (2) 13 5 — 18 13 5 — 18 Japanese debt securities: Government bonds 188 — — 188 179 — — 179 Pooled funds (2) — 9 — 9 — 10 — 10 Other — 23 — 23 — 21 — 21 Foreign equity securities: Common stocks 157 — — 157 172 — — 172 Pooled funds (2) — 6 — 6 — 7 — 7 Foreign debt securities: Government bonds 180 7 — 187 170 9 — 179 Pooled funds (2) — 12 — 12 — 10 — 10 Other — 19 — 19 — 18 — 18 General account of life insurance companies (3) — 115 — 115 — 116 — 116 Other 30 (4) (13 ) — 17 30 (4) (25 ) — 5 Plan assets measured at net asset value (5) 371 376 Total assets at fair value 1,859 183 — 2,413 1,567 171 — 2,114 Notes: (1) This class represents equity securities held in the employee retirement benefit trusts of ¥1,291 billion and ¥1,003 billion carried at fair value at March 31, 2021 and 2022, respectively, which are well-diversified across industries. (2) These classes primarily include pension investment fund trusts. Investments in these classes are generally measured at fair value and can be redeemed within a short-term period upon request. (3) Investments in this class are measured at conversion value, which is equivalent to fair value. (4) Amounts primarily include cash and short-term assets carried at fair value. (5) In accordance with ASC 820, certain plan assets that are measured at fair value using the net asset value per share (or its equivalent) practical expedient have not been classified in the fair value hierarchy.
Forecasted Benefit Payments Including Effect of Expected Future Service	The following table presents forecasted benefit payments including the effect of expected future service for the fiscal years indicated: (in millions of yen) Fiscal year ending March 31: 2023 76,933 2024 76,956 2025 76,662 2026 77,281 2027 75,557 2028-2032 344,156

Stock-based compensation (Table

Stock-based compensation (Tables)	12 Months Ended
	Mar. 31, 2022
Share-based Payment Arrangement [Abstract]
Summary of Stock-Based Compensation Plan	The following is a roll-forward of MHFG Stock Plan for the fiscal year ended March 31, 2022: Number of shares Weighted-average exercise price Weighted-average remaining contractual term Aggregate intrinsic value (in yen) (in years) (in millions of yen) Outstanding at beginning of fiscal year 85,700 1 Exercised during fiscal year 24,200 1 Outstanding at end of fiscal year 61,500 1 11.58 96 Exercisable at end of fiscal year — — — —
Activities Related to Stock Compensation Program	The following table presents activities related to the stock compensation programs for the fiscal years ended March 31, 2021 and 2022: Stock Compensation I Stock Compensation II 2021 Number of shares Weighted-average grant-date fair value Number of shares Weighted-average grant-date fair value (per share in yen) (per share in yen) Nonvested at the beginning of the year — — 1,142,329 1,775.08 Granted during fiscal year 365,074 1,390.08 730,726 1,390.08 Vested during fiscal year 365,074 1,390.08 245,266 1,665.35 Forfeited during fiscal year — — — — Nonvested at the end of the year — — 1,627,789 1,618.79 Stock Compensation I Stock Compensation II 2022 Number of shares Weighted-average grant-date fair value Number of shares Weighted-average grant-date fair value (per share in yen) (per share in yen) Nonvested at the beginning of the year — — 1,627,789 1,618.79 Granted during fiscal year 329,839 1,570.97 732,161 1,570.97 Vested during fiscal year 329,839 1,570.97 293,856 1,614.11 Forfeited during fiscal year — — — — Nonvested at the end of the year — — 2,066,094 1,602.51
Total Fair Value of Stock Compensation that Vested and Common Stock Acquired	The following table presents the total fair value of the stock compensation that vested and the total amount of the common stock acquired from the stock market by the trustee for the fiscal years ended March 31, 2021 and 2022: 2021 2022 Stock Compensation I Stock Compensation II Stock Compensation I Stock Compensation II (in millions of yen) Fair value of vested shares 507 221 518 463 Common stock shares acquired 507 1,016 518 1,150
Schedule Of Stock-Based Compensation Expense	The following table presents the compensation cost recognized in the stock compensation programs for the fiscal years ended March 31, 2020, 2021 and 2022: 2020 2021 2022 (in millions of yen) Stock Compensation I 917 507 518 Stock Compensation II 1,247 1,053 1,013

Derivative financial instrume_2

Derivative financial instruments (Tables)	12 Months Ended
	Mar. 31, 2022
Summary of Notional and Fair Value Amounts of Derivative Instruments Outstanding	The following table summarizes the notional and fair value amounts of derivative instruments outstanding as of March 31, 2021 and 2022. The fair values of derivatives are presented on a gross basis; derivative receivables and payables are not offset. In addition, they are not offset against the amounts recognized for the right to reclaim cash collateral or the obligation to return cash collateral under master netting agreements in the consolidated balance sheets, or the table below. Fair value Derivative receivables (2) Derivative payables (2) 2021 Notional amount (1) Designated as hedges Not designated as hedges Designated as hedges Not designated as hedges (in billions of yen) Interest rate contracts 1,174,835 — 4,639 — 4,476 Foreign exchange contracts 182,809 — 3,328 — 3,246 Equity-related contracts 7,865 — 531 — 384 Credit-related contracts 10,431 — 94 — 113 Other contracts 413 — 33 — 33 Total 1,376,353 — 8,625 — 8,252 Fair value Derivative receivables (2) Derivative payables (2) 2022 Notional amount (1) Designated as hedges Not designated as hedges Designated as hedges Not designated as hedges (in billions of yen) Interest rate contracts 1,395,950 — 4,624 — 4,716 Foreign exchange contracts 217,462 — 4,436 — 4,472 Equity-related contracts 9,887 — 426 — 345 Credit-related contracts 11,857 — 118 — 121 Other contracts 681 — 119 — 116 Total 1,635,837 — 9,723 — 9,770 Notes: (1) Notional amount includes the sum of gross long and gross short third-party contracts. (2) Derivative receivables and payables are recorded in Trading account assets and Trading account liabilities, respectively.
Summary of Notional and Fair Value Amounts of Credit Derivatives	The following table summarizes the notional and fair value amounts of credit derivatives at March 31, 2021 and 2022: 2021 2022 Notional amount Fair value Notional amount Fair value (in billions of yen) Credit protection written: Investment grade 3,687 71 3,045 38 Non-investment 872 17 2,122 54 Total 4,559 88 5,167 92 Credit protection purchased 5,872 (107 ) 6,690 (95 ) Note: The rating scale is based upon either the external ratings or the internal ratings of the underlying reference credit. The lowest investment grade rating is considered to be BBB - non-investment Non-investment
Maximum Potential Amount of Future Payments for Credit Protection Written by Expiration Period	The following table shows the maximum potential amount of future payments for credit protection written by expiration period at March 31, 2021 and 2022: Maximum payout/Notional amount 2021 2022 (in billions of yen) One year or less 249 245 After one year through five years 4,184 4,785 After five years 126 137 Total 4,559 5,167 Note: The maximum potential amount of future payments is the aggregate notional amount of the credit derivatives where the Group wrote the credit protection, and it has not been reduced by the effect of any amounts that the Group may possibly collect on the underlying assets and the related cash flows, nor netted against that of credit protection purchased.
Not Designated as Hedging Instrument
Schedule of Derivative Instruments, Gain (Loss) in Statement of Financial Performance	The following table summarizes gains and losses on derivatives not designated or qualifying as hedges during the fiscal years ended March 31, 2020, 2021 and 2022: Gains (losses) recorded in income 2020 2021 2022 (in millions of yen) Interest rate contracts 388,289 (27,893 ) (130,312 ) Foreign exchange contracts (111,920 ) 115,181 145,979 Equity-related contracts 217,744 (209,488 ) 728,226 Credit-related contracts (Note) 8,046 (58,602 ) (13,877 ) Other contracts (21,143 ) 23,680 7,762 Total 481,016 (157,122 ) 737,778 Note: Amounts include the net gains (losses) of million, ¥(2,956) million and ¥(605) million on the credit derivatives economically managing the credit risk of loans during the fiscal years ended March 31, 2020, 2021 and 2022, respectively.
Quantitative Information about Derivative Instruments with Credit-risk-related Contingent Features	The following table shows the quantitative information about derivative instruments with credit-risk-related contingent features at March 31, 2021 and 2022: 2021 2022 (in billions of yen) Aggregate fair value of derivative instruments with credit-risk-related contingent features in net liability positions 780 1,149 Collateral provided to counterparties in the normal course of business 584 1,164 Amount required to be posted as collateral or settled immediately if credit-risk-related contingent features were triggered 196 —
Net Investment Hedging | Designated as Hedging Instrument
Schedule of Derivative Instruments, Gain (Loss) in Statement of Financial Performance	The following table summarizes gains and losses information related to net investment hedges for the fiscal years ended March 31, 2020, 2021 and 2022: Gains (losses) recorded in other comprehensive income (“OCI”) 2020 2021 2022 (in millions of yen) Financial instruments hedging foreign exchange risk 418 1,483 (1,267 ) Total 418 1,483 (1,267 ) Note: No amount related to the net investment hedges was reclassified from Accumulated other comprehensive income to earnings for the fiscal year ended March 31, 2022. Related million were reclassified from Accumulated other comprehensive income to earnings for the fiscal years ended March 31, 2020, 2021, respectively.

Commitments and contingencies (

Commitments and contingencies (Tables)	12 Months Ended
	Mar. 31, 2022
Summary of Maximum Potential Amount of Future Payments under Guarantees	The MHFG Group, when necessary, requires collateral such as cash, investment securities and real estate or third-party guarantees depending on the amount of credit risk involved, and employs means such as sub-participation 2021 Maximum potential/Contractual or Notional amount Amount by expiration period One year or After one year through five years After five years (in billions of yen) Performance guarantees 2,730 1,662 882 186 Guarantees on loans 348 242 84 22 Guarantees on securities 79 23 56 — Other guarantees 2,390 1,913 348 129 Guarantees for the repayment of trust principal 28 — 13 15 Liabilities of trust accounts 480 61 235 184 Derivative financial instruments 23,933 8,821 12,048 3,064 2022 Maximum potential/Contractual or Notional amount Amount by expiration period One year or After one year through five years After five years (in billions of yen) Performance guarantees 3,254 2,084 996 174 Guarantees on loans 419 314 42 63 Guarantees on securities 75 9 66 — Other guarantees 2,899 2,381 451 67 Guarantees for the repayment of trust principal 22 — 9 13 Liabilities of trust accounts 478 116 199 163 Derivative financial instruments 36,484 17,110 15,721 3,653
Summary of Contractual Amounts with Regard to Undrawn Commitments	The table below summarizes the contractual amounts with regard to these undrawn commitments at March 31, 2021 and 2022: 2021 2022 (in billions of yen) Commitments to extend credit (Note) 93,999 92,203 Commercial letters of credit 797 1,422 Total 94,796 93,625 Note: Commitments to extend credit include commitments to invest in securities.
Schedule of Balance Sheet Information Related to operating lease	The following table presents the consolidated balance sheet information related to operating leases as of March 31, 2021 and 2022: 2021 2022 (in millions of yen, except for remaining lease Right-of-use (Note) 611,533 570,171 Lease liabilities (Note) 636,541 593,339 Weighted average: Remaining lease term 15.6 years 15.5 years Discount rate 0.54 % 0.60 % Note: Right-of-use
Schedule of operating lease cost and supplemental cash flow information	The following table presents lease cost and supplemental information related to operating leases for the fiscal years ended March 31, 2020, 2021 and 2022: 2020 2021 2022 (in millions of yen) Lease cost (Note) 126,840 119,453 111,907 Right-of-use 60,047 108,430 51,901 Operating cash flows 102,066 102,150 101,223 Note: Lease cost for operating leases are included in Occupancy expenses on the consolidated statements of income. The Group’s variable lease costs and costs for leases with terms of twelve months or less are not significant.
Future Minimum Lease Payments for Capitalized Leases and Rental Payments for Operating Leases	The following table shows future lease payments under operating leases as of March 31, 2022: As of March 31, 2022 (in millions of yen) Fiscal year ending March 31: 2023 82,330 2024 60,138 2025 52,311 2026 41,991 2027 32,854 2028 and thereafter 347,734 Total lease payments 617,358 Amount representing interest 24,019 Total lease liabilities for operating leases 593,339
Performance guarantees, Guarantees on loans, Guarantees on securities and Other guarantees
Summary of Maximum Potential Amount of Future Payments under Guarantees	The table below presents the maximum potential amount of future payments of performance guarantees, guarantees on loans, guarantees on securities and other guarantees classified based on internal ratings at March 31, 2021 and 2022: 2021 2022 (in billions of yen) Investment grade 4,427 5,336 Non-investment 1,120 1,311 Total 5,547 6,647 Note: Investment grade in the internal rating scale generally corresponds to BBB-

Variable interest entities an_2

Variable interest entities and securitizations (Tables)	12 Months Ended
	Mar. 31, 2022
Schedule of Variable Interest Entities	The table below shows the consolidated assets of the Group’s consolidated VIEs as well as total assets and maximum exposure to loss for its significant unconsolidated VIEs, in which the Group has determined that its maximum exposure to loss is greater than specific thresholds or meets certain other criteria as of March 31, 2021 and 2022: Consolidated VIEs Significant unconsolidated VIEs 2021 Consolidated assets Total assets Maximum exposure to loss (in billions of yen) Asset-backed commercial paper/loan programs 2,628 — — Asset-backed securitizations 921 127 48 Investments in securitization products 390 — — Investment funds 2,299 3,219 768 Trust arrangements and other 5,535 — — Total 11,773 3,346 816 Consolidated VIEs Significant unconsolidated VIEs 2022 Consolidated assets Total assets Maximum exposure to loss (in billions of yen) Asset-backed commercial paper/loan programs 2,709 — — Asset-backed securitizations 1,363 190 90 Investments in securitization products 388 — — Investment funds 1,816 3,392 719 Trust arrangements and other 5,299 — — Total 11,575 3,582 809
Unconsolidated VIEs
Schedule of Variable Interest Entities	The tables below present the carrying amounts and classification of assets and liabilities on the MHFG Group’s balance sheets that relate to its variable interests in significant unconsolidated VIEs, as of March 31, 2021 and 2022: Assets on the MHFG Group’s balance sheets related to unconsolidated VIEs: 2021 2022 (in billions of yen) Trading account assets 127 143 Investments 513 430 Loans 66 92 Total 706 665 Liabilities on the MHFG Group’s balance sheets and maximum exposure to loss related to unconsolidated VIEs: 2021 2022 (in billions of yen) Payables under securities lending transactions 53 54 Trading account liabilities 2 2 Total 55 56 Maximum exposure to loss (Note) 816 809 Note: This represents the maximum amount the Group could possibly be required to record in its consolidated statements of income associated with on-balance-sheet off-balance-sheet

Noninterest income (Tables)

Noninterest income (Tables)	12 Months Ended
	Mar. 31, 2022
Summary of Noninterest Income	Details of Noninterest income for the fiscal years ended March 31, 2020, 2021 and 2022 are as follows: 2020 2021 2022 (in millions of yen) Fee and commission income: Securities-related business (1) 139,124 170,216 184,014 Deposits-related business (1) 14,668 15,162 15,358 Lending-related business (2)(4) 142,752 158,921 162,953 Remittance business (1) 112,275 109,111 103,979 Asset management business (1) 98,720 104,753 122,014 Trust-related business (1) 129,298 122,215 141,365 Agency business (1) 31,879 31,331 36,899 Guarantee-related business (3) 28,974 31,665 35,296 Fees for other customer services (1) 170,195 169,310 178,122 Total Fee and commission income 867,885 912,684 980,000 Foreign exchange gains (losses)—net (3) 44,345 89,267 91,611 Trading account gains (losses)—net (2) 745,692 120,596 (491,947 ) Investment gains (losses)—net: Debt securities (3) 31,032 (22,032 ) (14,777 ) Equity securities (3) (557,391 ) 850,567 (60,563 ) Equity in earnings (losses) of equity method investees—net (3) 34,012 31,027 34,587 Gains on disposal of premises and equipment (3) 2,583 7,125 9,943 Other noninterest income (2)(5) 139,582 52,086 120,936 Total 1,307,740 2,041,320 669,790 Notes: (1) These amounts are revenues from contracts within the scope of ASC 606, “Revenue from contracts with customers” (“ASC 606”). (2) Part of these amounts are considered to be revenues from contracts that are within the scope of ASC 606. (3) These amounts are revenues from contracts that do not meet the scope of ASC 606. (4) Most of the lending-related fees such as commitment fees and arrangement fees are not within the scope of ASC 606. (5) These amounts include the net unrealized gains resulting from changes in fair values of structured notes that contain embedded derivatives. See Note 27 “Fair value” for further details.

Trading account gains and los_2

Trading account gains and losses (Tables)	12 Months Ended
	Mar. 31, 2022
Trading Account Gains And Losses [Abstract]
Net Trading Gains and Losses	Net trading gains (losses) for the fiscal years ended March 31, 2020, 2021 and 2022 are comprised of the following: 2020 2021 2022 (in millions of yen) Trading account gains (losses)—net: Trading securities 267,514 274,762 (1,230,330 ) Derivative contracts: Interest rate contracts 388,289 (27,893 ) (130,312 ) Foreign exchange contracts (1) (111,920 ) 115,181 145,979 Equity-related contracts 217,744 (209,488 ) 728,226 Credit-related contracts (2) 5,208 (55,646 ) (13,272 ) Other contracts (21,143 ) 23,680 7,762 Total 745,692 120,596 (491,947 ) Foreign exchange gains (losses)—net (3) 44,345 89,267 91,611 Net trading gains (losses) 790,037 209,863 (400,336 ) Notes: (1) Amounts include gains and losses on currency swaps. ( 2 Amounts do not include the net gains (losses) of ¥2,838 million, ¥(2,956) million and ¥(605) million on the credit derivatives economically managing the credit risk of loans during the fiscal years ended March 31, 2020, 2021 and 2022, respectively. The net gains (losses) is recorded in Other noninterest income (expenses). ( 3 Amounts include realized and unrealized gains and losses on both derivative instruments and nonderivative instruments. Amounts on derivative instruments include gains and losses on forward foreign exchange contracts and currency options. Amounts on nonderivative instruments include translation gains and losses related to foreign currency-denominated debt securities reported as Trading securities.

Fair value (Tables)

Fair value (Tables)	12 Months Ended
	Mar. 31, 2022
Summary of Assets and Liabilities Measured at Fair Value on a Recurring Basis, Including Fair Value Option Elected	Assets and liabilities measured at fair value on a recurring basis at March 31, 2021 and 2022, including those for which the MHFG Group has elected the fair value option, are summarized below: 2021 Level 1 Level 2 Level 3 Assets/ Liabilities measured at fair value (in billions of yen) Assets: Trading securities (1) : Japanese government bonds 1,923 11 — 1,934 Japanese local government bonds — 120 — 120 U.S. Treasury bonds and federal agency securities 3,544 604 — 4,148 Other foreign government bonds 775 500 — 1,275 Agency mortgage-backed securities — 4,727 — 4,727 Residential mortgage-backed securities — — 9 9 Certificates of deposit and commercial paper — 1,204 — 1,204 Corporate bonds and other (2) 34 1,638 1,033 2,705 Equity securities 1,220 326 29 1,575 Trading securities measured at net asset value (3) 431 Derivative financial instruments: Interest rate contracts 63 4,564 12 4,639 Foreign exchange contracts — 3,304 24 3,328 Equity-related contracts 170 339 22 531 Credit-related contracts — 91 3 94 Other contracts 10 6 17 33 2021 Level 1 Level 2 Level 3 Assets/ Liabilities measured at fair value (in billions of yen) Available-for-sale Japanese government bonds 20,598 323 — 20,921 Japanese local government bonds — 463 — 463 U.S. Treasury bonds and federal agency securities 911 — — 911 Other foreign government bonds 535 972 — 1,507 Agency mortgage-backed securities — 521 — 521 Residential mortgage-backed securities — 48 23 71 Commercial mortgage-backed securities — — 716 716 Japanese corporate bonds and other debt securities — 1,539 365 1,904 Foreign corporate bonds and other debt securities — 707 132 839 Equity securities: Equity securities with readily determinable fair values 3,375 104 — 3,479 Equity securities measured at net asset value (3) 121 Other investments 2 — 53 55 Total assets measured at fair value on a recurring basis 33,160 22,111 2,438 58,261 Liabilities: Trading securities sold, not yet purchased 2,138 488 — 2,626 Derivative financial instruments: Interest rate contracts 64 4,408 4 4,476 Foreign exchange contracts — 3,245 1 3,246 Equity-related contracts 224 117 43 384 Credit-related contracts — 112 1 113 Other contracts 7 9 17 33 Long-term debt (4) — 1,990 713 2,703 Total liabilities measured at fair value on a recurring basis 2,433 10,369 779 13,581 2022 Level 1 Level 2 Level 3 Assets/ Liabilities measured at fair value (in billions of yen) Assets: Trading securities (1) : Japanese government bonds 1,604 11 — 1,615 Japanese local government bonds — 145 — 145 U.S. Treasury bonds and federal agency securities 2,353 711 — 3,064 Other foreign government bonds 907 639 — 1,546 Agency mortgage-backed securities — 3,176 — 3,176 Residential mortgage-backed securities — — 8 8 Certificates of deposit and commercial paper — 640 — 640 Corporate bonds and other (2) 15 2,743 71 2,829 Equity securities 1,381 213 28 1,622 Trading securities measured at net asset value (3) 284 Derivative financial instruments: Interest rate contracts 89 4,513 22 4,624 Foreign exchange contracts — 4,404 32 4,436 Equity-related contracts 77 323 26 426 Credit-related contracts — 116 2 118 Other contracts 49 18 52 119 Available-for-sale Japanese government bonds 24,662 497 — 25,159 Japanese local government bonds — 420 — 420 U.S. Treasury bonds and federal agency securities 373 — — 373 Other foreign government bonds 363 973 — 1,336 Agency mortgage-backed securities — 451 — 451 Residential mortgage-backed securities — 40 18 58 Commercial mortgage-backed securities — 854 — 854 Japanese corporate bonds and other debt securities — 1,920 315 2,235 Foreign corporate bonds and other debt securities — 671 117 788 Equity securities: Equity securities with readily determinable fair values 3,094 61 — 3,155 Equity securities measured at net asset value (3) 210 Other investments 2 — 56 58 Total assets measured at fair value on a recurring basis 34,969 23,539 747 59,749 Liabilities: Trading securities sold, not yet purchased 3,054 2,035 — 5,089 Derivative financial instruments: Interest rate contracts 80 4,636 — 4,716 Foreign exchange contracts — 4,472 — 4,472 Equity-related contracts 122 183 40 345 Credit-related contracts — 120 1 121 Other contracts 28 36 52 116 Long-term debt (4) — 1,962 794 2,756 Total liabilities measured at fair value on a recurring basis 3,284 13,444 887 17,615 Notes: (1) Trading securities include foreign currency denominated securities for which the MHFG Group elected the fair value option. (2) The amount includes CLO and convertible bonds, which are classified in Level 3. (3) In accordance with ASC 820, certain investments that are measured at fair value using the net asset value per share (or its equivalent) practical expedient have not been classified in the fair value hierarchy. The fair value amounts presented for these classes of assets are intended to permit the reconciliation of the fair value hierarchy to the amounts presented in the statements of financial position. The amounts of unfunded commitments related to these investments at March 31, 2021 and 2022 were ¥55 billion and ¥68 billion, respectively. (4) Amounts represent items for which the Group elected the fair value option or for which it applied the practicability exception.
Reconciliation for All Assets and Liabilities Measured at Fair Value on a Recurring Basis Using Significant Unobservable Inputs (Level 3)	The following table presents a reconciliation for all assets and liabilities measured at fair value on a recurring basis using significant unobservable inputs (Level 3) for the fiscal years ended March 31, 2021 and 2022: 2021 April 1, 2020 Gains (losses) in Earnings Gains (losses) in OCI Transfers into Level 3 Transfers out of Level 3 Purchases Sales Issuances Settle- ments March 31, 2021 Change in unrealized gains (losses) still held (6) (in billions of yen) Assets: Trading securities: Residential mortgage- backed securities 10 — (2) — — — — — — (1 ) 9 — Corporate bonds and other 1,115 70 (2) — — (1 ) 443 (216 ) — (378 ) 1,033 65 Equity securities 30 1 (2) — — — 2 (3 ) — (1 ) 29 — Derivative financial instruments, net (1) Interest rate contracts (5 ) 4 (2) — — — — — — 9 8 13 Foreign exchange contracts 16 9 (2) — — — — — — (2 ) 23 10 Equity-related contracts (17 ) 1 (2) — — — — — — (5 ) (21 ) (17 ) Credit-related contracts (2 ) 4 (2) — 1 1 — — — (2 ) 2 1 Other contracts 1 — (2) — — — — — — (1 ) — — Available-for-sale Residential mortgage- 31 — (3) — (4) — — — — — (8 ) 23 — Commercial mortgage-backed securities 615 — (3) 1 (4) — — 181 (78 ) — (3 ) 716 — Japanese corporate bonds and other debt securities 157 (13 ) (3) 6 (4) — (22 ) 391 (118 ) — (36 ) 365 (8 ) Foreign corporate bonds and other debt securities 174 7 (3) 16 (4) 12 — 36 — — (113 ) 132 — Other investments 39 2 (3) — — — 38 (6 ) — (20 ) 53 1 Liabilities: Trading securities sold, not yet purchased — — (2) — — — (1 ) 1 — — — — Long-term debt 621 (66 ) (5) (19 ) (4) 20 (42 ) — — 374 (345 ) 713 (34 ) 2022 April 1, 2021 Gains (losses) in Earnings Gains (losses) in OCI Transfers into Level 3 Transfers out of Level 3 Purchases Sales Issuances Settle- ments March 31, 2022 Change in unrealized gains (losses) still held (6) (in billions of yen) Assets: Trading securities: Residential mortgage-backed securities 9 — (2) — — — — — — (1 ) 8 — Corporate bonds and other 1,033 7 (2) — — (452 ) 143 (72 ) — (588 ) 71 3 Equity securities 29 — (2) — — — — — — (1 ) 28 1 Derivative financial instruments, net (1) Interest rate contracts 8 11 (2) — — — — — — 3 22 (22 ) Foreign exchange contracts 23 8 (2) — — — — — — 1 32 7 Equity-related contracts (21 ) (11 ) (2) — — — — — — 18 (14 ) (23 ) Credit-related contracts 2 (3 ) (2) — — — — — — 2 1 (1 ) Other contracts — 1 (2) — — — — — — (1 ) — — Available-for-sale Residential mortgage-backed securities 23 — (3) — (4) — — — — — (5 ) 18 — Commercial mortgage-backed securities 716 5 (3) (5 ) (4) — (689 ) 62 (60 ) — (29 ) — — Japanese corporate bonds and other debt securities 365 (20 ) (3) 1 (4) — (4 ) 11 — — (38 ) 315 (19 ) Foreign corporate bonds and other debt 132 — (3) 7 (4) — (4 ) 47 — — (65 ) 117 1 Other investments 53 2 (3) — — — 37 (3 ) — (33 ) 56 (2 ) Liabilities: Trading securities sold, not yet purchased — — (2) — — — — — — — — — Long-term deb t 713 61 (5) 1 (4) 4 (6 ) — — 534 (389 ) 794 77 Notes: (1) Total Level 3 derivative exposures have been netted on the table for presentation purposes only. (2) Gains (losses) in Earnings are reported in Trading account gains (losses)—net, Foreign exchange gains (losses)—net or Other noninterest income (expenses). (3) Gains (losses) in Earnings are reported in Investment gains (losses)—net. (4) Gains (losses) in OCI are reported in Other comprehensive income (loss). (5) Gains (losses) in Earnings are reported in Other noninterest income (expenses). (6) Amounts represent total gains or losses recognized in earnings and OCI during the period. These gains or losses were attributable to the change in fair value relating to assets and liabilities classified as Level 3 that were still held at March 31, 2021 and 2022. The amounts of unrealized gains (losses) in OCI related to Available-for-sale
Quantitative Information about Significant Unobservable Inputs Related to Material Classes of Level 3 Assets and Liabilities	Quantitative information about Level 3 fair value measurements The following table presents information about significant unobservable inputs related to the MHFG Group’s material classes of Level 3 assets and liabilities at March 31, 2021 and 2022: 2021 Products/Instruments Fair value Principal valuation technique Unobservable inputs Range of input values Average (4) (in billions of yen, except for percentages and basis points) Trading securities and Available-for-sale Residential mortgage-backed securities 32 Discounted cash flow Price-based Prepayment rate Default rate Recovery rate Discount margin 2%–17% 0%–1% 100%–100% 28bps–170bps 7% 0% 100% 51bps Commercial mortgage-backed securities 716 Discounted cash flow Price-based Discount margin 5 bps 22bps Corporate bonds and other 1,530 Discounted cash flow Price-based Prepayment rate (1) Default rate (1) Recovery rate (1) Discount margin (1) Discount margin (2) 10%–18% 1%–24% 10%–68% 45bps–143bps 4bps–507bps 18% 2% 66% 115bps 284bps Derivative financial instruments, net: Interest rate contracts 8 Internal valuation model (3) IR – IR correlation 35 % – 76% Foreign exchange contracts 23 Internal valuation model (3) FX – IR correlation FX – FX correlation 23%–50% 43%–65% 30% 54% Equity-related contracts (21 ) Internal valuation model (3) Equity – IR correlation Equity correlation Equity volatility 25%–25% 0%–100% 8%–71% 25% 88% 41% Credit-related contracts 2 Internal valuation model (3) Default rate Credit correlation 0%–5% 40%–100% 1% 66% Other contracts — Internal valuation model (3) Commodity volatility 0%–63% 33% Long-term debt 713 Internal valuation model (3) IR – IR correlation 49 % 78% FX – IR correlation 23%–50% 36% FX – FX correlation 43%–65% 54% Equity – IR correlation 25%–25% 25% Equity – FX correlation -33%–50% 0% Equity correlation 0%–100% 88% Equity volatility 8%–71% 29% Default rate 0%–5% 1% Credit correlation 17%–100% 68% 2022 Products/Instruments Fair value Principal valuation technique Unobservable inputs Range of input values Average (4) (in billions of yen, except for percentages and basis points) Trading securities and Available-for-sale Residential mortgage-backed securities 26 Discounted cash flow Prepayment rate 0%–18% 6% Price-based Default rate 0%–0% 0% Recovery rate 100%–100% 100% Discount margin 30bps–167bps 53bps Corporate bonds and other debt securities 503 Discounted cash flow Prepayment rate (1) 6%–24% 24% Price-based Default rate (1) 0%–60% 1% Recovery rate (1) 10%–40% 39% Discount margin (1) 35bps–103bps 47bps Discount margin (2) 4bps–447bps 340bps Derivative financial instruments, net: Interest rate contracts 22 Internal valuation model (3) IR – IR correlation 23%–100% 75% Foreign exchange contracts 32 Internal valuation model (3) FX – IR correlation 11%–52% 31% FX – FX correlation 41%–65% 53% Equity-related contracts (14 ) Internal valuation model (3) Equity – IR correlation 25%–25% 25% Equity correlation 3%–100% 90% Equity volatility 13%–121% 47% Credit-related contracts 1 Internal valuation model (3) Default rate 0%–8% 1% Credit correlation 43%–100% 66% Other contracts — Internal valuation model (3) Commodity volatility 0%–89% 55% Long-term debt 794 Internal valuation model (3) IR – IR correlation 23%–100% 75% FX – IR correlation 11%–52% 39% FX – FX correlation 41%–65% 53% Equity – IR correlation 25%–25% 25% Equity – FX correlation -17%–17% 0% Equity correlation 3%–100% 90% Equity volatility 9%–121% 34% Default rate 0%–8% 1% Credit correlation 19%–100% 64% Notes: (1) These inputs are mainly used for determining the fair values of securitization products such as CDO, CLO and ABS, other than RMBS and CMBS. (2) This input is mainly used for determining the fair values of Japanese corporate bonds and foreign corporate bonds. (3) Internal valuation model includes discounted cash flow models and the Black-Scholes option pricing model. (4) Averages are calculated by weighting each input by the relative fair value of the respective financial instruments except for derivative related inputs where medians are used. IR = Interest rate FX = Foreign exchange
Summary of Assets and Liabilities Measured at Fair Value on a Nonrecurring Basis	The following table shows the fair value hierarchy for these items as of March 31, 2021 and 2022: 2021 Total Level 1 Level 2 Level 3 Aggregate cost (in billions of yen) Assets: Loans 85 — 3 82 167 Loans held-for-sale 22 — 21 1 23 Equity securities (without readily determinable fair values) 3 — — 3 4 Premises and equipment—net — — — — 7 Other assets 24 — — 24 34 Total assets measured at fair value on a nonrecurring basis 134 — 24 110 235 2022 Total Level 1 Level 2 Level 3 Aggregate cost (in billions of yen) Assets: Loans 81 — — 81 128 Loans held-for-sale 76 — 27 49 77 Equity securities (without readily determinable fair values) 4 — 3 1 4 Premises and equipment—net — — — — 13 Other ass e — — — — 3 Total assets measured at fair value on a nonrecurring basi s 161 — 30 131 225 Note: The fair values may not be current as of the dates indicated, but rather as of the date the fair value change occurred. Accordingly, the carrying values may not equal current fair value.
Carrying Amounts and Fair Values of Certain Financial Instruments, Excluding Financial Instruments Carried at Fair Value on a Recurring Basis and Those outside Scope of ASC 825	The following table shows the carrying amounts and fair values at March 31, 2021 and 2022, of certain financial instruments, excluding financial instruments which are carried at fair value on a recurring basis and those outside the scope of ASC 825 such as equity method investments as defined in ASC 323, “Investments-Equity Method and Joint Ventures” (“ASC 323”) and lease contracts as defined in ASC 842, “Leases” (“ASC 842”): 2021 Carrying amount Estimated fair value Total Level 1 Level 2 Level 3 (in billions of yen) Financial assets: Cash and due from banks, interest-bearing deposits in other banks, call loans and funds sold, and receivables under resale agreements and securities borrowing transactions 63,910 63,910 47,441 16,469 — Investments 887 904 490 414 — Loans, net of allowance for loan losses (Note) 87,708 88,845 — — 88,845 Financial liabilities: Noninterest-bearing deposits, call money and funds purchased, and payables under repurchase agreements and securities lending transactions 53,278 53,278 — 53,278 — Interest-bearing deposits 118,860 118,849 — 118,849 — Due to trust accounts 381 381 — 381 — Other short-term borrowings 9,086 9,086 — 9,086 — Long-term debt 9,034 9,219 — 7,847 1,372 2022 Carrying amount Estimated fair value Total Level 1 Level 2 Level 3 (in billions of yen) Financial assets: Cash and due from banks, interest-bearing deposits in other banks, call loans and funds sold, and receivables under resale agreements and securities borrowing transactions 68,366 68,366 50,628 17,738 — Investments 1,519 1,466 485 981 — Loans, net of allowance for loan losses (Note) 89,264 90,576 — — 90,576 Financial liabilities: Noninterest-bearing deposits, call money and funds purchased, and payables under repurchase agreements and securities lending transactions 58,054 58,054 — 58,054 — Interest-bearing deposits 121,833 121,807 — 121,807 — Due to trust accounts 390 390 — 390 — Other short-term borrowings 7,567 7,567 — 7,567 — Long-term debt 9,849 9,681 — 8,162 1,519 Note: Loans, net of allowance include items measured at fair value on a nonrecurring basis.

Offsetting of financial asset_2

Offsetting of financial assets and financial liabilities (Tables)	12 Months Ended
	Mar. 31, 2022
Information of Offsetting of Financial Assets and Financial Liabilities	The following table provides information about the offsetting of financial assets and financial liabilities at March 31, 2021 and 2022. The table includes derivatives, repurchase and resale agreements, and securities lending and borrowing transactions that are subject to enforceable master netting arrangements or similar agreements irrespective of whether or not they are offset on the Group’s consolidated balance sheets. Amounts not offset on the balance sheet (3) Gross amounts recognized Gross amounts offset on the balance sheet Net amounts presented on the balance sheet (2) Financial instruments (4) Cash collateral Net amounts (in billions of yen) 2021 Assets (1) : Derivatives 8,625 — 8,625 (5) (6,323 ) (588 ) 1,714 Receivables under resale agreements 11,623 — 11,623 (6) (10,478 ) — 1,145 Receivables under securities borrowing transactions 2,694 — 2,694 (7) (2,621 ) — 73 Total 22,942 — 22,942 (19,422 ) (588 ) 2,932 Liabilities (1) : Derivatives 8,252 — 8,252 (5) (6,033 ) (933 ) 1,286 Payables under repurchase agreements 18,607 — 18,607 (6) (17,979 ) — 628 Payables under securities lending transactions 1,208 — 1,208 (7) (953 ) — 255 Total 28,067 — 28,067 (24,965 ) (933 ) 2,169 2022 Assets (1) : Derivatives 9,723 — 9,723 (5) (7,232 ) (891 ) 1,600 Receivables under resale agreements 12,751 — 12,751 (6) (11,437 ) — 1,314 Receivables under securities borrowing transactions 2,339 — 2,339 (7) (2,299 ) — 40 Total 24,813 — 24,813 (20,968 ) (891 ) 2,954 Liabilities (1) : Derivatives 9,770 — 9,770 (5) (6,716 ) (1,329 ) 1,725 Payables under repurchase agreements 20,070 — 20,070 (6) (19,366 ) — 704 Payables under securities lending transactions 1,361 — 1,361 (7) (1,164 ) — 197 Total 31,201 — 31,201 (27,246 ) (1,329 ) 2,626 Notes: (1) Amounts relating to master netting arrangements or similar agreements where the MHFG Group does not have the legal right of set-off over-the-counter OTC-cleared (2) Derivative assets and liabilities are recorded in Trading account assets and Trading account liabilities, respectively. (3) Amounts do not exceed the net amounts presented on the balance sheet and do not include the effect of overcollateralization, where it exists. (4) For derivatives, amounts include derivative assets or liabilities and securities collateral that are eligible for offsetting under enforceable master netting arrangements or similar agreements. (5) The amounts of derivative assets and liabilities subject to enforceable master netting arrangements or similar agreements were ¥8,168 billion and ¥7,652 billion, respectively, at March 31, 2021, and ¥9,326 billion and ¥9,235 billion, respectively, at March 31, 2022. (6) The amounts of Receivables under resale agreements and Payables under repurchase agreements subject to enforceable industry standard master repurchase agreements with netting terms were ¥10,551 billion and ¥18,321 billion, respectively, at March 31, 2021, and ¥11,537 billion and ¥19,505 billion respectively, at March 31, 2022. (7) The amounts of Receivables under securities borrowing transactions and Payables under securities lending transactions subject to enforceable industry standard master lending agreements with netting terms were ¥2,694 billion and ¥958 billion, respectively, at March 31, 2021, and ¥2,339 billion and ¥1,172 billion respectively, at March 31, 2022.

Repurchase agreements and sec_2

Repurchase agreements and securities lending transactions accounted for as secured borrowings (Tables)	12 Months Ended
	Mar. 31, 2022
Gross Amounts of Liabilities by Remaining Contractual Maturity	The following table shows the gross amounts of liabilities associated with repurchase agreements and securities lending transactions, by remaining contractual maturity at March 31, 2021 and 2022: Overnight and continuous Up to 30 days 31-90 days Greater than 90 days Total (in billions of yen) 2021 Repurchase agreements 9,459 3,586 4,315 1,247 18,607 Securities lending transactions 943 15 — 250 1,208 Total 10,402 3,601 4,315 1,497 19,815 2022 Repurchase agreements 7,011 10,621 1,340 1,098 20,070 Securities lending transactions 1,098 74 — 189 1,361 Total 8,109 10,695 1,340 1,287 21,431
Gross Amounts of Liabilities by Class of Underlying Collateral	The following table shows the gross amounts of liabilities associated with repurchase agreements and securities lending transactions, by class of underlying collateral at March 31, 2021 and 2022: Repurchase agreements Securities lending transactions (in billions of yen) 2021 Japanese government bonds and Japanese local government bonds 1,787 352 Foreign government bonds and foreign agency mortgage-backed securities 15,917 131 Commercial paper and corporate bonds 284 57 Equity securities 544 654 Other 75 14 Total 18,607 1,208 2022 Japanese government bonds and Japanese local government bonds 1,714 217 Foreign government bonds and foreign agency mortgage-backed securities 17,445 90 Commercial paper and corporate bonds 271 52 Equity securities 609 989 Other 31 13 Total 20,070 1,361

Related Party Transactions (Tab

Related Party Transactions (Table)	12 Months Ended
	Mar. 31, 2022
Related Party Transactions [Abstract]
Summary of financial information of groups equity method investees	Summarized financial information of the MHFG Group’s equity method investees as of March 31, 2021 and 2022, and for each of the three years ended March 31, 2022, is as follows: 2021 2022 (in billions of yen) Loans 7,521 7,765 Total assets 29,540 30,180 Deposits 10,301 8,713 Total liabilities 27,247 27,474 Total equity 2,293 2,706 Noncontrolling interests 13 14 2020 2021 2022 (in billions of yen) Total interest and dividend income 586 570 625 Total interest expense 198 188 182 Provision (credit) for credit losses 81 91 104 Net interest income after provision (credit) for credit losses 307 291 339 Income before income tax expense 196 237 332 Net income 150 178 246

Business segment information (T

Business segment information (Tables)	12 Months Ended
	Mar. 31, 2022
Reportable Segment Information Derived from Internal Management Reporting Systems, on Basis of Japanese GAAP	The reportable segment information, set forth below, is derived from the internal management reporting systems used by management to measure the performance of the Group’s operating segments. Management measures the performance of each of the operating segments in accordance with internal managerial accounting rules and practices. In addition, the format and information are presented primarily on the basis of Japanese GAAP. Therefore, they are not consistent with the consolidated financial statements prepared in accordance with U.S. GAAP. A reconciliation is provided for the total amount of all business segments’ “Net business profits (losses) + Net gains (losses) related to ETFs and others” with income before income tax expense under U.S. GAAP, and the total amount of all business segments’ “Fixed assets” with the total amount of Premises and equipment-net, right-of-use MHFG (Consolidated) 2020 (1) Retail & Business Banking Company Corporate & Institutional Company Global Corporate Company Global Markets Company Asset Management Company Others (6) Total (in billions of yen) Gross profits + Net gains (losses) related to ETFs and others (2) 693.9 440.5 417.1 414.5 53.3 53.5 2,072.8 General and administrative expenses (3) 670.2 214.8 253.4 202.9 33.1 37.1 1,411.5 Equity in earnings (losses) of equity method investees—net 11.7 2.0 10.4 — 1.3 5.0 30.4 Amortization of goodwill and others 2.8 0.1 0.4 1.1 7.8 1.0 13.2 Others — — — — — (5.9 ) (5.9 ) Net business profits (losses) (4) 32.6 227.6 173.7 210.5 13.7 14.5 672.6 Fixed assets (5) 517.0 205.7 168.0 96.8 0.1 752.2 1,739.8 MHFG (Consolidated) 2021 (1) Retail & Business Banking Company Corporate & Institutional Company Global Corporate Company Global Markets Company Asset Management Company Others (6) Total (in billions of yen) Gross profits + Net gains (losses) related to ETFs and others (2) 697.7 472.8 456.0 490.3 50.8 33.2 2,200.8 General and administrative expenses (3) 639.6 206.5 259.1 217.7 33.0 52.8 1,408.7 Equity in earnings (losses) of equity method investees—net 5.5 3.9 10.9 — 1.1 (1.5 ) 19.9 Amortization of goodwill and others 2.3 0.1 0.4 0.8 7.6 1.0 12.2 Others — — — — — — — Net business profits (losses) (4) 61.3 270.1 207.4 271.8 11.3 (22.1 ) 799.8 Fixed assets (5) 543.9 193.5 169.1 98.4 — 750.8 1,755.7 MHFG (Consolidated) 2022 (1) Retail & Business Banking Company Corporate & Institutional Company Global Corporate Company Global Markets Company Asset Management Company Others (6) Total (in billions of yen) Gross profits + Net gains (losses) related to ETFs and others (2) 713.7 491.7 518.8 378.9 59.5 91.9 2,254.5 General and administrative expenses (3) 621.0 198.1 267.7 227.6 33.4 67.2 1,415.0 Equity in earnings (losses) of equity method investees—net 5.9 3.8 13.2 — 1.4 1.1 25.4 Amortization of goodwill and others 2.2 0.1 0.4 0.8 7.2 1.0 11.7 Others — — — — — — — Net business profits (losses) (4) 96.4 297.3 263.9 150.5 20.3 24.8 853.2 Fixed assets (5) 504.2 160.2 161.5 88.8 — 782.6 1,697.3 Notes: (1) Income and expenses of foreign branches of MHBK and foreign subsidiaries with functional currencies other than Japanese Yen have been translated for purposes of segment reporting using the budgeted foreign currency rates. Prior period comparative amounts for such foreign currency income and expenses have been translated using current period budgeted foreign currency rates. (2) “Gross profits + Net gains (losses) related to ETFs and others” is reported instead of sales reported by general corporations. Gross profits is defined as the sum of net interest income, fiduciary income, net fee and commission income, net trading income and net other operating income. Net gains (losses) related to ETFs and others consist of net gains (losses) on ETFs held by MHBK and MHTB on their non-consolidated (3) “General and administrative expenses” excludes non-allocated (4) Net business profits (losses) is used in Japan as a measure of the profitability of core banking operations, and is defined as gross profits (as defined above) less general and administrative expenses (excluding non-allocated (5) “Fixed assets” is presented based on Japanese GAAP and corresponds to the total amount of the following U.S. GAAP accounts: Premises and equipment-net; right-of-use (6) “Others” includes the following items: • profits and expenses pertaining to consolidated subsidiaries that are not subject to allocation; • consolidating adjustments, including elimination of internal transaction between each segment; • equity in earnings (losses) of equity method investees-net • profits and losses pertaining to derivative transactions that reflect the counterparty risk of the individual parties and other factors in determining fair market value.
Reconciliation of Total Net Business Profits under Internal Management Reporting Systems to Income Before Income Tax Expense on Consolidated Statements of Income	A reconciliation of “Net business profits (losses) + Net gains (losses) related to ETFs and others” for the fiscal years ended March 31, 2020, 2021 and 2022 presented above to income before income tax expense shown on the consolidated statements of income and a reconciliation of “Fixed assets” at March 31, 2021 and 2022 to the total amount of Premises and equipment-net, right-of-use 2020 2021 2022 (in billions of yen) Net business profits (losses) + Net gains (losses) related to ETFs and others 672.6 799.8 853.2 Adjustment to reconcile management reporting to Japanese GAAP: General and administrative expenses: non-allocated 46.3 6.3 33.7 Expenses related to portfolio problems (including reversal of (provision for) general reserve for losses on loans) (183.3 ) (209.9 ) (255.9 ) Gains on reversal of reserves for possible losses on loans, and others 11.6 4.9 20.8 Net gains (losses) related to stocks—Net gains (losses) related to ETFs and others 126.6 10.1 (45.8 ) Net extraordinary gains (losses) (19.2 ) 115.9 44.0 Others (35.9 ) (74.9 ) (46.1 ) Income before income tax expense under Japanese GAAP 618.7 652.2 603.9 Adjustment to reconcile Japanese GAAP to U.S. GAAP: Derivative financial instruments and hedging activities 111.2 (86.4 ) (124.0 ) Investments (480.9 ) 523.5 (600.1 ) Loans (3.0 ) (16.9 ) (18.3 ) Allowances for credit losses (1) 0.7 83.3 51.5 Premises and equipment (96.1 ) (56.5 ) (68.5 ) Land revaluation 2.1 6.4 6.4 Business combinations 6.0 (1.0 ) 6.9 Pension liabilities (56.7 ) (153.2 ) (94.4 ) Consolidation of variable interest entities 39.3 104.6 42.3 Foreign currency translation 17.3 (31.5 ) (51.0 ) Others (5.1 ) 4.3 2.8 Income before income tax expense under U.S. GAAP 153.5 1,028.8 (242.5 )
Reconciliation of Assets from Segment to Consolidated	2020 2021 2022 (in billions of yen) Fixed assets 1,739.8 1,755.7 1,697.3 U.S. GAAP adjustments (2) 887.2 816.1 717.6 Premises and equipment-net, right-of-use 2,627.0 2,571.8 2,414.9 Notes: (1) The MHFG Group adopted ASU No.2016-13, 2019-04, 2019-05, 2019-11 off-balance-sheet (2) The U.S. GAAP adjustments are primarily comprised of GAAP differences mainly from right-of-use

Foreign activities (Tables)

Foreign activities (Tables)	12 Months Ended
	Mar. 31, 2022
Text Block [Abstract]
Consolidated Income Statement and Total Assets Information by Major Geographic Area	The following table presents consolidated income statement and total assets information by major geographic area. Foreign activities are defined as business transactions that involve customers residing outside of Japan. However, as the MHFG Group’s operations are highly integrated globally, estimates and assumptions have been made for an allocation among the geographic areas. Americas Japan United States of America Others Europe Asia/Oceania excluding Japan, and others Total (in billions of yen) Fiscal year ended March 31, 2020: Total revenue (1) 1,681.0 801.5 95.1 270.4 610.9 3,458.9 Total expenses (2) 2,008.9 679.2 41.5 239.1 336.7 3,305.4 Income (loss) before income tax expense (benefit) (327.9 ) 122.3 53.6 31.3 274.2 153.5 Net income (loss) (312.8 ) 100.4 51.5 23.6 243.6 106.3 Total assets at end of fiscal year 137,470.4 34,650.4 4,137.3 15,487.0 19,473.7 211,218.8 Fiscal year ended March 31, 2021: Total revenue (1) 2,290.8 503.8 154.5 188.7 360.1 3,497.9 Total expenses (2) 1,918.2 243.5 14.4 115.8 177.2 2,469.1 Income before income tax expense 372.6 260.3 140.1 72.9 182.9 1,028.8 Net income 235.6 227.4 137.2 60.9 156.9 818.0 Total assets at end of fiscal year 152,613.7 31,939.9 4,405.3 14,150.6 18,542.0 221,651.5 Fiscal year ended March 31, 2022: Total revenue (1) 991.1 562.9 41.7 184.8 333.2 2,113.7 Total expenses (2) 1,713.8 265.0 19.0 189.2 169.2 2,356.2 Income (loss) before income tax expense (benefit) (722.7 ) 297.9 22.7 (4.4 ) 164.0 (242.5 ) Net income (loss) (509.0 ) 275.2 18.3 (16.3 ) 130.3 (101.5 ) Total assets at end of fiscal year 155,111.2 36,765.7 3,667.9 15,795.9 20,210.0 231,550.7 Notes: (1) Total revenue is comprised of Interest and dividend income and Noninterest income. (2) Total expenses are comprised of Interest expense, Provision (credit) for credit losses and Noninterest expenses.

Mizuho Financial Group, Inc.,_2

Mizuho Financial Group, Inc., parent company (Tables)	12 Months Ended
	Mar. 31, 2022
Condensed Financial Information Disclosure [Abstract]
Condensed Balance Sheets	Condensed balance sheets 2021 2022 (in millions of yen) Assets: Cash and due from banking subsidiaries 44,619 51,356 Interest-bearing deposits in banking subsidiaries 347 414 Investments in subsidiaries and affiliated companies: Banking subsidiaries 8,561,350 8,102,149 Non-banking 1,241,783 878,776 Long-term loans receivable from subsidiaries: A banking subsidiary 7,851,894 7,942,367 A non-banking — 399,000 Other 549,068 648,946 Total 18,249,061 18,023,008 Liabilities and shareholders’ equity: Short-term borrowings from a banking subsidiary 850,000 755,000 Long-term debt 7,875,414 7,957,710 Other liabilities 418,409 396,086 Shareholders’ equity 9,105,238 8,914,212 Total 18,249,061 18,023,008
Condensed Statements of Income	Condensed statements of income 2020 2021 2022 (in millions of yen) Income: Dividends from subsidiaries and affiliated companies: Banking subsidiaries 23,824 214,473 197,717 Non-banking 12,850 17,499 82,105 Management fees from subsidiaries 38,004 36,334 40,462 Interest income on loans and discounts 123,354 128,697 133,215 Gains on disposal of premises and equipment 10,866 — — Gains on sales of investments in subsidiaries — 40 53,005 Other income 7,088 11,970 11,319 Total 215,986 409,013 517,823 Expenses: Operating expenses 38,951 37,979 43,192 Interest expense 126,516 130,812 130,453 Losses on sales of investments in a subsidiary — — 26,606 Other expense 25,313 8,842 5,946 Total 190,780 177,633 206,197 Equity in undistributed net income (loss) of subsidiaries 130,930 341,369 (505,891 ) Income (loss) before income tax expense (benefit) 156,136 572,749 (194,265 ) Income tax expense (benefit) 5,941 (9,016 ) (89,543 ) Net income (loss ) 150,195 581,765 (104,722 )
Condensed Statements of Cash Flows	Condensed statements of cash flows 2020 2021 2022 (in millions of yen) Cash flows from operating activities: Net income (loss) 150,195 581,765 (104,722 ) Adjustments and other (92,059 ) (390,748 ) 351,484 Net cash provided by operating activities 58,136 191,017 246,762 Cash flows from investing activities: Net change in loans (1,496,047 ) (1,167,385 ) (72,313 ) Purchases of premises and equipment (43,406 ) (41,382 ) (26 ) Proceeds from sales of premises and equipment 209,657 55,624 11 Proceeds from sales of investments in subsidiaries 245 125 452,500 Net change in other investing activities (5,395 ) (1,370 ) 223 Net cash provided by (used in) investing activities (1,334,946 ) (1,154,388 ) 380,395 Cash flows from financing activities: Net change in short-term borrowings (85,505 ) (10,000 ) (95,000 ) Proceeds from issuance of long-term debt 1,531,047 1,477,385 930,033 Repayment of long-term debt (35,000 ) (310,000 ) (1,256,720 ) Purchases of treasury stock (1,441 ) (1,849 ) (1,927 ) Dividends paid (190,386 ) (190,498 ) (196,783 ) Net change in other financing activities 962 65 44 Net cash provided by (used in) financing activities 1,219,677 965,103 (620,353 ) Net increase (decrease) in cash and cash equivalents (57,133 ) 1,732 6,804 Cash and cash equivalents at beginning of fiscal year 100,367 43,234 44,966 Cash and cash equivalents at end of fiscal year 43,234 44,966 51,770

Basis of Presentation and Sum_4

Basis of Presentation and Summary of Significant Accounting Policies - Additional Information (Detail)	12 Months Ended
	Mar. 31, 2022
Minimum
Disclosure of Accounting Policies [Line Items]
Period in which obligors generally determined to be substantially bankrupt, past due (in months)	6 months
Minimum | Software and Software Development Costs
Disclosure of Accounting Policies [Line Items]
Estimated useful life	5 years
Maximum | Software and Software Development Costs
Disclosure of Accounting Policies [Line Items]
Estimated useful life	10 years
Impaired loans | Minimum
Disclosure of Accounting Policies [Line Items]
Number of days past due	90 days
Customer Relationships [Member] | Shinko Securities Company Limited
Disclosure of Accounting Policies [Line Items]
Weighted-average amortization period	16 years
Customer Relationships [Member] | Asset Management Company
Disclosure of Accounting Policies [Line Items]
Weighted-average amortization period	16 years 10 months 24 days

Basis of Presentation and Sum_5

Basis of Presentation and Summary of Significant Accounting Policies (Useful Lives of Premises and Equipment) (Detail)	12 Months Ended
	Mar. 31, 2022
Minimum | Buildings
Disclosure of Basis of Presentation and Summary of Significant Accounting Policies [Line Items]
Years	3 years
Minimum | Equipment and furniture
Disclosure of Basis of Presentation and Summary of Significant Accounting Policies [Line Items]
Years	2 years
Maximum | Buildings
Disclosure of Basis of Presentation and Summary of Significant Accounting Policies [Line Items]
Years	50 years
Maximum | Equipment and furniture
Disclosure of Basis of Presentation and Summary of Significant Accounting Policies [Line Items]
Years	20 years

Investments - Amortized Cost, G

Investments - Amortized Cost, Gross Unrealized Gains and Losses, and Fair Value of Available-for-Sale and Held-to-Maturity Securities (Detail) - JPY (¥) ¥ in Millions		Mar. 31, 2022	Mar. 31, 2021
Schedule of Investments [Line Items]
Gross unrealized losses, available-for-sale securities		¥ 58,803	¥ 41,389
Fair value, available-for-sale securities		31,673,890	27,853,035
Amortized cost, held-to-maturity securities		1,519,055	887,149
Total		1,465,576
Debt securities | Japanese government bonds
Schedule of Investments [Line Items]
Gross unrealized losses, available-for-sale securities		38,379	34,562
Amortized cost, held-to-maturity securities		479,980
Total		485,081
Debt securities | Japanese local government bonds
Schedule of Investments [Line Items]
Gross unrealized losses, available-for-sale securities		2,165	658
Debt securities | U.S. Treasury bonds and federal agency securities
Schedule of Investments [Line Items]
Gross unrealized losses, available-for-sale securities		8,444	46
Debt securities | Other foreign government bonds
Schedule of Investments [Line Items]
Gross unrealized losses, available-for-sale securities		2,578	209
Debt securities | Agency mortgage-backed securities
Schedule of Investments [Line Items]
Gross unrealized losses, available-for-sale securities	[1]	3,985	687
Amortized cost, held-to-maturity securities		1,039,075
Total		980,495
Debt securities | Residential mortgage-backed securities
Schedule of Investments [Line Items]
Gross unrealized losses, available-for-sale securities		312	188
Debt securities | Commercial mortgage-backed securities
Schedule of Investments [Line Items]
Gross unrealized losses, available-for-sale securities		214	39
Debt securities | Japanese corporate bonds and other debt securities
Schedule of Investments [Line Items]
Gross unrealized losses, available-for-sale securities		1,705	3,574
Debt securities | Foreign corporate bonds and other debt securities
Schedule of Investments [Line Items]
Gross unrealized losses, available-for-sale securities		1,021	1,426
Available-for-sale securities | Debt securities
Schedule of Investments [Line Items]
Amortized cost, net available-for-sale securities	[2],[3]	31,702,397	27,856,703
Gross unrealized gains, available-for-sale securities		30,296	37,721
Gross unrealized losses, available-for-sale securities		58,803	41,389
Fair value, available-for-sale securities		31,673,890	27,853,035
Available-for-sale securities | Debt securities | Japanese government bonds
Schedule of Investments [Line Items]
Amortized cost, net available-for-sale securities	[2],[3]	25,191,315	20,953,200
Gross unrealized gains, available-for-sale securities		5,794	1,945
Gross unrealized losses, available-for-sale securities		38,379	34,562
Fair value, available-for-sale securities		25,158,730	20,920,583
Available-for-sale securities | Debt securities | Japanese local government bonds
Schedule of Investments [Line Items]
Amortized cost, net available-for-sale securities	[2],[3]	421,557	463,673
Gross unrealized gains, available-for-sale securities		254	544
Gross unrealized losses, available-for-sale securities		2,165	658
Fair value, available-for-sale securities		419,646	463,559
Available-for-sale securities | Debt securities | U.S. Treasury bonds and federal agency securities
Schedule of Investments [Line Items]
Amortized cost, net available-for-sale securities	[2],[3]	381,653	906,499
Gross unrealized gains, available-for-sale securities		0	4,440
Gross unrealized losses, available-for-sale securities		8,444	46
Fair value, available-for-sale securities		373,209	910,893
Available-for-sale securities | Debt securities | Other foreign government bonds
Schedule of Investments [Line Items]
Amortized cost, net available-for-sale securities	[2],[3]	1,338,295	1,505,770
Gross unrealized gains, available-for-sale securities		220	1,975
Gross unrealized losses, available-for-sale securities		2,578	209
Fair value, available-for-sale securities		1,335,937	1,507,536
Available-for-sale securities | Debt securities | Agency mortgage-backed securities
Schedule of Investments [Line Items]
Amortized cost, net available-for-sale securities	[2],[3],[4]	452,830	512,720
Gross unrealized gains, available-for-sale securities	[4]	1,695	8,746
Gross unrealized losses, available-for-sale securities	[4]	3,985	687
Fair value, available-for-sale securities	[4]	450,540	520,779
Available-for-sale securities | Debt securities | Residential mortgage-backed securities
Schedule of Investments [Line Items]
Amortized cost, net available-for-sale securities	[2],[3]	58,246	70,111
Gross unrealized gains, available-for-sale securities		194	761
Gross unrealized losses, available-for-sale securities		312	188
Fair value, available-for-sale securities		58,128	70,684
Available-for-sale securities | Debt securities | Commercial mortgage-backed securities
Schedule of Investments [Line Items]
Amortized cost, net available-for-sale securities	[2],[3]	848,568	709,938
Gross unrealized gains, available-for-sale securities		5,437	6,196
Gross unrealized losses, available-for-sale securities		214	39
Fair value, available-for-sale securities		853,791	716,095
Available-for-sale securities | Debt securities | Japanese corporate bonds and other debt securities
Schedule of Investments [Line Items]
Amortized cost, net available-for-sale securities	[2],[3]	2,222,670	1,897,117
Gross unrealized gains, available-for-sale securities		14,212	10,537
Gross unrealized losses, available-for-sale securities		1,705	3,574
Fair value, available-for-sale securities		2,235,177	1,904,080
Available-for-sale securities | Debt securities | Foreign corporate bonds and other debt securities
Schedule of Investments [Line Items]
Amortized cost, net available-for-sale securities	[2],[3],[5]	787,263	837,675
Gross unrealized gains, available-for-sale securities	[5]	2,490	2,577
Gross unrealized losses, available-for-sale securities	[5]	1,021	1,426
Fair value, available-for-sale securities	[5]	788,732	838,826
Held-to-maturity Securities | Debt securities
Schedule of Investments [Line Items]
Amortized cost, held-to-maturity securities	[2],[3]	1,519,055	887,149
Gross unrealized gains, held-to-maturity securities		5,125	19,733
Gross unrealized losses, held-to-maturity securities		58,604	3,273
Total		1,465,576	903,609
Held-to-maturity Securities | Debt securities | Japanese government bonds
Schedule of Investments [Line Items]
Amortized cost, held-to-maturity securities	[2],[3]	479,980	479,959
Gross unrealized gains, held-to-maturity securities		5,101	9,555
Gross unrealized losses, held-to-maturity securities		0	0
Total		485,081	489,514
Held-to-maturity Securities | Debt securities | Agency mortgage-backed securities
Schedule of Investments [Line Items]
Amortized cost, held-to-maturity securities	[2],[3],[6]	1,039,075	407,190
Gross unrealized gains, held-to-maturity securities	[6]	24	10,178
Gross unrealized losses, held-to-maturity securities	[6]	58,604	3,273
Total	[6]	¥ 980,495	¥ 414,095
[1]Agency mortgage-backed securities presented in this line consist of Japanese agency mortgage-backed securities, of which the fair values were ¥107,077 million at March 31, 2021, and ¥261,867 million at March 31, 2022. All Japanese agency mortgage-backed securities are issued by Japan Housing Finance Agency, a Japanese government-sponsored enterprise.[2]Accrued interest receivables are excluded from amortized cost, of which the amount were ¥10,379 million at March 31, 2021, and ¥4,702 million at March 31, 2022 and included in Accrued income.[3]Amortized cost, net of the allowance for credit losses, of which the amounts related to available-for-sale securities were ¥13,617 million at March 31, 2021, and ¥34,326 million at March 31, 2022.[4]Agency mortgage-backed securities presented in this line consist of Japanese and Foreign agency mortgage-backed securities, of which the fair values were ¥520,746 million and ¥33 million, respectively, at March 31, 2021, and ¥450,507 million and ¥33 million, respectively, at March 31, 2022. All Japanese agency mortgage-backed securities are issued by Japan Housing Finance Agency, a Japanese government-sponsored enterprise. Foreign agency mortgage-backed securities primarily consist of Government National Mortgage Association (“Ginnie Mae”) securities, which are guaranteed by the United States government.[5]Other debt securities presented in this line primarily consist of Foreign negotiable certificates of deposit (“NCDs”) and asset-backed securities (“ABS”), of which the total fair values were ¥275,661 million at March 31, 2021, and ¥247,762 million at March 31, 2022.[6]All Agency mortgage-backed securities presented in this line are Ginnie Mae securities.

Investments - Amortized Cost,_2

Investments - Amortized Cost, Gross Unrealized Gains and Losses, and Fair Value of Available-for-Sale and Held-to-Maturity Securities (Parenthetical) (Detail) - JPY (¥) ¥ in Millions	Mar. 31, 2022	Mar. 31, 2021
Schedule of Investments [Line Items]
Fair value, available-for-sale securities	¥ 31,673,890	¥ 27,853,035
Net of Allowance for Credit Loss [Member]
Schedule of Investments [Line Items]
Amortised cost net of allowance for credit loss available for sale securities	34,326	13,617
Debt securities | Negotiable certificates of deposits, asset- backed securities and collateral loan obligations
Schedule of Investments [Line Items]
Fair value, available-for-sale securities	247,762	275,661
Debt securities | Japanese agency mortgage-backed securities | Agency mortgage-backed securities
Schedule of Investments [Line Items]
Fair value, available-for-sale securities	450,507	520,746
Debt securities | Foreign agency mortgage-backed securities | Agency mortgage-backed securities
Schedule of Investments [Line Items]
Fair value, available-for-sale securities	33	33
Available-for sale and held-to-maturity securities | Accrued Income [Member]
Schedule of Investments [Line Items]
Accrued interest receivables	¥ 4,702	¥ 10,379

Investments (Amortized Cost and

Investments (Amortized Cost and Fair Value of Available-for-Sale and Held-to-Maturity Securities by Contractual Maturity) (Detail) - JPY (¥) ¥ in Millions	Mar. 31, 2022	Mar. 31, 2021
Investments Classified by Contractual Maturity Date [Line Items]
Due in one year or less, amortized cost	¥ 21,054,835
Due after one year through five years, amortized cost	6,855,513
Due after five years through ten years, amortized cost	2,630,644
Due after ten years, amortized cost	1,161,405
Total	31,702,397
Due in one year or less, amortized cost	100,023
Due after one year through five years, amortized cost	379,957
Due after five years through ten years, amortized cost	0
Due after ten years, amortized cost	1,039,075
Amortized cost, held-to-maturity securities	1,519,055	¥ 887,149
Due in one year or less, fair value	21,052,114
Due after one year through five years, fair value	6,839,958
Due after five years through ten years, fair value	2,615,937
Due after ten years, fair value	1,165,881
Total	31,673,890
Due in one year or less, fair value	100,650
Due after one year through five years, fair value	384,431
Due after five years through ten years, fair value	0
Due after ten years, fair value	980,495
Total	1,465,576
Debt securities | Japanese government bonds
Investments Classified by Contractual Maturity Date [Line Items]
Due in one year or less, amortized cost	19,242,514
Due after one year through five years, amortized cost	4,160,143
Due after five years through ten years, amortized cost	1,681,312
Due after ten years, amortized cost	107,346
Total	25,191,315
Due in one year or less, amortized cost	100,023
Due after one year through five years, amortized cost	379,957
Due after five years through ten years, amortized cost	0
Due after ten years, amortized cost	0
Amortized cost, held-to-maturity securities	479,980
Due in one year or less, fair value	19,241,161
Due after one year through five years, fair value	4,151,094
Due after five years through ten years, fair value	1,663,395
Due after ten years, fair value	103,080
Total	25,158,730
Due in one year or less, fair value	100,650
Due after one year through five years, fair value	384,431
Due after five years through ten years, fair value	0
Due after ten years, fair value	0
Total	485,081
Debt securities | Japanese local government bonds
Investments Classified by Contractual Maturity Date [Line Items]
Due in one year or less, amortized cost	27,258
Due after one year through five years, amortized cost	220,168
Due after five years through ten years, amortized cost	166,619
Due after ten years, amortized cost	7,512
Total	421,557
Due in one year or less, fair value	27,279
Due after one year through five years, fair value	219,972
Due after five years through ten years, fair value	164,987
Due after ten years, fair value	7,408
Total	419,646
Debt securities | U.S. Treasury bonds and federal agency securities
Investments Classified by Contractual Maturity Date [Line Items]
Due in one year or less, amortized cost	82,287
Due after one year through five years, amortized cost	299,366
Due after five years through ten years, amortized cost	0
Due after ten years, amortized cost	0
Total	381,653
Due in one year or less, fair value	81,742
Due after one year through five years, fair value	291,467
Due after five years through ten years, fair value	0
Due after ten years, fair value	0
Total	373,209
Debt securities | Other foreign government bonds
Investments Classified by Contractual Maturity Date [Line Items]
Due in one year or less, amortized cost	1,066,461
Due after one year through five years, amortized cost	269,579
Due after five years through ten years, amortized cost	1,129
Due after ten years, amortized cost	1,126
Total	1,338,295
Due in one year or less, fair value	1,065,814
Due after one year through five years, fair value	267,868
Due after five years through ten years, fair value	1,129
Due after ten years, fair value	1,126
Total	1,335,937
Debt securities | Agency mortgage-backed securities
Investments Classified by Contractual Maturity Date [Line Items]
Due in one year or less, amortized cost	0
Due after one year through five years, amortized cost	0
Due after five years through ten years, amortized cost	0
Due after ten years, amortized cost	452,830
Total	452,830
Due in one year or less, amortized cost	0
Due after one year through five years, amortized cost	0
Due after five years through ten years, amortized cost	0
Due after ten years, amortized cost	1,039,075
Amortized cost, held-to-maturity securities	1,039,075
Due in one year or less, fair value	0
Due after one year through five years, fair value	0
Due after five years through ten years, fair value	0
Due after ten years, fair value	450,540
Total	450,540
Due in one year or less, fair value	0
Due after one year through five years, fair value	0
Due after five years through ten years, fair value	0
Due after ten years, fair value	980,495
Total	980,495
Debt securities | Residential mortgage-backed securities
Investments Classified by Contractual Maturity Date [Line Items]
Due in one year or less, amortized cost	0
Due after one year through five years, amortized cost	0
Due after five years through ten years, amortized cost	0
Due after ten years, amortized cost	58,246
Total	58,246
Due in one year or less, fair value	0
Due after one year through five years, fair value	0
Due after five years through ten years, fair value	0
Due after ten years, fair value	58,128
Total	58,128
Debt securities | Commercial mortgage-backed securities
Investments Classified by Contractual Maturity Date [Line Items]
Due in one year or less, amortized cost	30,000
Due after one year through five years, amortized cost	444,413
Due after five years through ten years, amortized cost	374,155
Due after ten years, amortized cost	0
Total	848,568
Due in one year or less, fair value	30,004
Due after one year through five years, fair value	446,606
Due after five years through ten years, fair value	377,181
Due after ten years, fair value	0
Total	853,791
Debt securities | Japanese corporate bonds and other debt securities
Investments Classified by Contractual Maturity Date [Line Items]
Due in one year or less, amortized cost	154,142
Due after one year through five years, amortized cost	1,275,410
Due after five years through ten years, amortized cost	277,228
Due after ten years, amortized cost	515,890
Total	2,222,670
Due in one year or less, fair value	154,196
Due after one year through five years, fair value	1,276,212
Due after five years through ten years, fair value	278,697
Due after ten years, fair value	526,072
Total	2,235,177
Debt securities | Foreign corporate bonds and other debt securities
Investments Classified by Contractual Maturity Date [Line Items]
Due in one year or less, amortized cost	452,173
Due after one year through five years, amortized cost	186,434
Due after five years through ten years, amortized cost	130,201
Due after ten years, amortized cost	18,455
Total	787,263
Due in one year or less, fair value	451,918
Due after one year through five years, fair value	186,739
Due after five years through ten years, fair value	130,548
Due after ten years, fair value	19,527
Total	¥ 788,732

Investments - Additional Inform

Investments - Additional Information (Detail) - JPY (¥) ¥ in Millions	12 Months Ended
	Mar. 31, 2022	Apr. 01, 2022	Apr. 01, 2021	Mar. 31, 2021
Gain (Loss) on Securities [Line Items]
Equity method Investments, carrying value	¥ 519,552			¥ 460,025
Japanese corporate bonds and other debt securities
Gain (Loss) on Securities [Line Items]
Credit losses on available-for-sale securities	34,000		¥ 14,000	14,000
Debt securities, available-for-sale, allowance for credit loss, period increase (decrease)	20,000
Japanese government bonds
Gain (Loss) on Securities [Line Items]
Allowance for credit losses on held to maturity debt securities	¥ 0	¥ 0	¥ 0	0
Orient Corporation
Gain (Loss) on Securities [Line Items]
Percentage of proportionate share to the total outstanding common stock	49%
Chiba Kogya Bank LTD [Member]
Gain (Loss) on Securities [Line Items]
Percentage of proportionate share to the total outstanding common stock	16.89%
Joint Stock Commercial Bank Foreign Trade of Vietnam [Member]
Gain (Loss) on Securities [Line Items]
Percentage of proportionate share to the total outstanding common stock	15%
Mizuho Leasing Company LTD [Member]
Gain (Loss) on Securities [Line Items]
Percentage of proportionate share to the total outstanding common stock	23.49%
Matthew International Capital Management LLC [Member]
Gain (Loss) on Securities [Line Items]
Percentage of proportionate share to the total outstanding common stock	18.21%
Custody Bank of Japan Ltd [Member]
Gain (Loss) on Securities [Line Items]
Percentage of proportionate share to the total outstanding common stock	27%
Equity securities (marketable)
Gain (Loss) on Securities [Line Items]
Equity method Investments, carrying value	¥ 255,336			229,156
Equity method Investments, aggregated market values	¥ 456,195			¥ 424,267

Investments - Gross Unrealized

Investments - Gross Unrealized Losses and Fair Value of Available-for-Sale and Held-to-Maturity Securities, Aggregated by Length of Time that Individual Securities Have Been in a Continuous Unrealized Loss Position (Detail) - JPY (¥) ¥ in Millions		Mar. 31, 2022	Mar. 31, 2021
Gain (Loss) on Securities [Line Items]
Less than 12 months, Fair value, available-for-sale securities		¥ 21,846,469	¥ 11,342,861
Less than 12 months Gross unrealized losses, available-for-sale securities		26,771	5,059
12 months or more Fair value, available-for-sale securities		2,032,092	5,090,903
12 months or more Gross unrealized losses, available-for-sale securities		32,032	36,330
Total Fair value, available-for-sale securities		23,878,561	16,433,764
Total Gross unrealized losses, available-for-sale securities		58,803	41,389
Debt securities | Japanese government bonds
Gain (Loss) on Securities [Line Items]
Less than 12 months, Fair value, available-for-sale securities		19,407,878	9,998,772
Less than 12 months Gross unrealized losses, available-for-sale securities		11,377	1,924
12 months or more Fair value, available-for-sale securities		1,565,950	4,058,718
12 months or more Gross unrealized losses, available-for-sale securities		27,002	32,638
Total Fair value, available-for-sale securities		20,973,828	14,057,490
Total Gross unrealized losses, available-for-sale securities		38,379	34,562
Debt securities | Japanese local government bonds
Gain (Loss) on Securities [Line Items]
Less than 12 months, Fair value, available-for-sale securities		229,562	125,058
Less than 12 months Gross unrealized losses, available-for-sale securities		1,277	323
12 months or more Fair value, available-for-sale securities		136,733	130,384
12 months or more Gross unrealized losses, available-for-sale securities		888	335
Total Fair value, available-for-sale securities		366,295	255,442
Total Gross unrealized losses, available-for-sale securities		2,165	658
Debt securities | U.S. Treasury bonds and federal agency securities
Gain (Loss) on Securities [Line Items]
Less than 12 months, Fair value, available-for-sale securities		321,073	38,625
Less than 12 months Gross unrealized losses, available-for-sale securities		7,209	46
12 months or more Fair value, available-for-sale securities		41,555	0
12 months or more Gross unrealized losses, available-for-sale securities		1,235	0
Total Fair value, available-for-sale securities		362,628	38,625
Total Gross unrealized losses, available-for-sale securities		8,444	46
Debt securities | Other foreign government bonds
Gain (Loss) on Securities [Line Items]
Less than 12 months, Fair value, available-for-sale securities		729,134	576,415
Less than 12 months Gross unrealized losses, available-for-sale securities		2,178	209
12 months or more Fair value, available-for-sale securities		71,647	0
12 months or more Gross unrealized losses, available-for-sale securities		400	0
Total Fair value, available-for-sale securities		800,781	576,415
Total Gross unrealized losses, available-for-sale securities		2,578	209
Debt securities | Agency mortgage-backed securities
Gain (Loss) on Securities [Line Items]
Less than 12 months, Fair value, available-for-sale securities	[1]	183,150	70,088
Less than 12 months Gross unrealized losses, available-for-sale securities	[1]	2,326	120
12 months or more Fair value, available-for-sale securities	[1]	78,717	36,989
12 months or more Gross unrealized losses, available-for-sale securities	[1]	1,659	567
Total Fair value, available-for-sale securities	[1]	261,867	107,077
Total Gross unrealized losses, available-for-sale securities	[1]	3,985	687
Debt securities | Residential mortgage-backed securities
Gain (Loss) on Securities [Line Items]
Less than 12 months, Fair value, available-for-sale securities		9,221	9,270
Less than 12 months Gross unrealized losses, available-for-sale securities		11	52
12 months or more Fair value, available-for-sale securities		17,193	11,435
12 months or more Gross unrealized losses, available-for-sale securities		301	136
Total Fair value, available-for-sale securities		26,414	20,705
Total Gross unrealized losses, available-for-sale securities		312	188
Debt securities | Commercial mortgage-backed securities
Gain (Loss) on Securities [Line Items]
Less than 12 months, Fair value, available-for-sale securities		58,815	12,530
Less than 12 months Gross unrealized losses, available-for-sale securities		185	6
12 months or more Fair value, available-for-sale securities		13,939	10,351
12 months or more Gross unrealized losses, available-for-sale securities		29	33
Total Fair value, available-for-sale securities		72,754	22,881
Total Gross unrealized losses, available-for-sale securities		214	39
Debt securities | Japanese corporate bonds and other debt securities
Gain (Loss) on Securities [Line Items]
Less than 12 months, Fair value, available-for-sale securities		605,067	278,698
Less than 12 months Gross unrealized losses, available-for-sale securities		1,516	953
12 months or more Fair value, available-for-sale securities		53,020	843,026
12 months or more Gross unrealized losses, available-for-sale securities		189	2,621
Total Fair value, available-for-sale securities		658,087	1,121,724
Total Gross unrealized losses, available-for-sale securities		1,705	3,574
Debt securities | Foreign corporate bonds and other debt securities
Gain (Loss) on Securities [Line Items]
Less than 12 months, Fair value, available-for-sale securities		302,569	233,405
Less than 12 months Gross unrealized losses, available-for-sale securities		692	1,426
12 months or more Fair value, available-for-sale securities		53,338	0
12 months or more Gross unrealized losses, available-for-sale securities		329	0
Total Fair value, available-for-sale securities		355,907	233,405
Total Gross unrealized losses, available-for-sale securities		¥ 1,021	¥ 1,426
[1]Agency mortgage-backed securities presented in this line consist of Japanese agency mortgage-backed securities, of which the fair values were ¥107,077 million at March 31, 2021, and ¥261,867 million at March 31, 2022. All Japanese agency mortgage-backed securities are issued by Japan Housing Finance Agency, a Japanese government-sponsored enterprise.

Investments - Gross Unrealize_2

Investments - Gross Unrealized Losses and Fair Value of Available-for-Sale and Held-to-Maturity Securities, Aggregated by Length of Time that Individual Securities Have Been in a Continuous Unrealized Loss Position (Parenthetical) (Detail) - JPY (¥) ¥ in Millions		Mar. 31, 2022	Mar. 31, 2021
Gain (Loss) on Securities [Line Items]
Fair value, available-for-sale securities		¥ 23,878,561	¥ 16,433,764
Debt securities | Agency mortgage-backed securities
Gain (Loss) on Securities [Line Items]
Fair value, available-for-sale securities	[1]	261,867	107,077
Debt securities | Japanese agency mortgage-backed securities | Agency mortgage-backed securities
Gain (Loss) on Securities [Line Items]
Fair value, available-for-sale securities		¥ 261,867	¥ 107,077
[1]Agency mortgage-backed securities presented in this line consist of Japanese agency mortgage-backed securities, of which the fair values were ¥107,077 million at March 31, 2021, and ¥261,867 million at March 31, 2022. All Japanese agency mortgage-backed securities are issued by Japan Housing Finance Agency, a Japanese government-sponsored enterprise.

Investments - Realized Gains an

Investments - Realized Gains and Losses on Sales of Available-for-Sale Securities (Detail) - JPY (¥) ¥ in Millions	12 Months Ended
	Mar. 31, 2022	Mar. 31, 2021	Mar. 31, 2020
Debt Securities, Available-for-sale [Line Items]
Gross realized gains	¥ 12,540	¥ 3,309	¥ 41,903
Gross realized losses	(40,077)	(24,407)	(13,398)
Net realized gains (losses) on sales of available-for-sale securities	¥ (27,537)	¥ (21,098)	¥ 28,505

Investments - Summary of Detail

Investments - Summary of Details of Net Gains and Losses on Equity Securities (Detail) - JPY (¥) ¥ in Millions	12 Months Ended
	Mar. 31, 2022	Mar. 31, 2021	Mar. 31, 2020
Gain (Loss) on Securities [Line Items]
Net gains (losses) recognized during the period on equity securities	¥ (60,563)	¥ 850,567	¥ (557,391)
Less: Net gains (losses) recognized during the period on equity securities sold during the period	17,000	82,969	1,710
Unrealized gains (losses) recognized during the reporting period on equity securities still held at the reporting period	¥ (77,563)	¥ 767,598	¥ (559,101)

Investments - Summary of Equity

Investments - Summary of Equity Securities Without Readily Determinable Fair Values (Detail) - JPY (¥) ¥ in Millions	Mar. 31, 2022	Mar. 31, 2021	Mar. 31, 2020
Equity Securities without Readily Determinable Fair Value [Line Items]
Carrying amounts at the end of the period	¥ 207,407	¥ 186,146	¥ 419,775
Downward adjustments and impairments	6,519	5,087	2,435
Upward adjustments	¥ 11,623	¥ 9,216	¥ 9,128

Investments - Summary of Downwa

Investments - Summary of Downward Adjustments and Impairments and Upward Adjustments (Detail) - JPY (¥) ¥ in Millions	12 Months Ended
	Mar. 31, 2022	Mar. 31, 2021	Mar. 31, 2020
Equity Securities without Readily Determinable Fair Value [Line Items]
Downward adjustments and impairments	¥ 2,626	¥ 3,084	¥ 1,272
Upward adjustments	¥ 2,459	¥ 404	¥ 6,928

Investments - Summary of Compos

Investments - Summary of Composition of Other Investments (Detail) - JPY (¥) ¥ in Millions	Mar. 31, 2022	Mar. 31, 2021
Schedule of Investments [Line Items]
Equity method investments	¥ 519,552	¥ 460,025
Investments held by consolidated investment companies and other	62,836	55,321
Total	¥ 582,388	¥ 515,346

Loans - Additional Information

Loans - Additional Information (Detail) - JPY (¥) ¥ in Millions	12 Months Ended
	Mar. 31, 2022	Mar. 31, 2021	Mar. 31, 2020
Accounts, Notes, Loans and Financing Receivable [Line Items]
Net losses on sales of loans	¥ 3,080	¥ 8,172	¥ 1,036
Accrued Income Receivable [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accrued interest receivables	80,959	77,764
Impaired Financing Receivables with No Related Allowance
Accounts, Notes, Loans and Financing Receivable [Line Items]
Impaired loans partially charged off	¥ 13,046	¥ 20,197

Loans - Credit Quality Informat

Loans - Credit Quality Information of Loans Based on MHFG Group's Internal Rating System (Detail) - JPY (¥) ¥ in Millions	Mar. 31, 2022	Mar. 31, 2021
Normal obligors | Domestic | Retail | Housing Loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	¥ 798,354	¥ 785,194
2019	544,246	588,599
2018	518,662	588,535
2017	526,828	600,179
2016	543,893	741,969
Prior to 2016	4,752,430	4,599,546
Revolving loan	0	0
Total	7,684,413	7,904,022
Normal obligors | Domestic | Retail | Other
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	195,545	431,277
2019	277,015	154,675
2018	111,702	127,379
2017	90,880	88,649
2016	60,919	85,042
Prior to 2016	315,375	317,237
Revolving loan	497,173	526,703
Total	1,548,609	1,730,962
Watch obligors | Domestic | Retail | Housing Loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	1,512	2,041
2019	1,485	1,075
2018	1,510	1,566
2017	1,939	1,343
2016	1,226	2,127
Prior to 2016	40,243	39,046
Revolving loan	0	0
Total	47,915	47,198
Watch obligors | Domestic | Retail | Other
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	23,586	50,212
2019	34,974	14,288
2018	10,177	10,450
2017	7,995	5,888
2016	4,122	3,713
Prior to 2016	6,388	5,796
Revolving loan	9,491	10,545
Total	96,733	100,892
Non Accrual Loans | Domestic | Retail | Housing Loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	12,510	20,706
2019	3,132	2,268
2018	802	1,399
2017	1,180	1,421
2016	970	1,640
Prior to 2016	30,598	35,135
Revolving loan	0	0
Total	49,192	62,569
Non Accrual Loans | Domestic | Retail | Other
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	6,932	32,594
2019	7,862	2,086
2018	3,157	1,145
2017	4,253	901
2016	4,076	837
Prior to 2016	22,951	8,780
Revolving loan	12,602	12,557
Total	61,833	58,900
Financing Receivables Not Impaired
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	30,801,993	32,546,989
2019	12,276,604	13,017,576
2018	10,120,851	11,493,988
2017	7,631,537	4,770,628
2016	3,494,760	4,060,946
Prior to 2016	11,019,544	9,508,600
Revolving loan	14,945,294	13,182,140
Total	90,290,583	88,580,867
Financing Receivables Not Impaired | Domestic
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	15,071,530	18,340,767
2019	8,261,149	7,937,280
2018	6,610,993	8,546,670
2017	5,925,471	3,613,978
2016	2,714,739	3,392,467
Prior to 2016	9,735,707	8,293,428
Revolving loan	8,712,068	8,444,369
Total	57,031,657	58,568,959
Financing Receivables Not Impaired | Foreign
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	15,730,463	14,206,222
2019	4,015,455	5,080,296
2018	3,509,858	2,947,318
2017	1,706,066	1,156,650
2016	780,021	668,479
Prior to 2016	1,283,837	1,215,172
Revolving loan	6,233,226	4,737,771
Total	33,258,926	30,011,908
Financing Receivables Not Impaired | Normal obligors | Domestic | Soverign
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	938,534	1,466,468
2019	105,966	80,260
2018	89,385	128,702
2017	108,664	71,943
2016	54,580	75,389
Prior to 2016	351,876	389,777
Revolving loan	1,864	12,615
Total	1,650,869	2,225,154
Financing Receivables Not Impaired | Normal obligors | Domestic | Banks and other financial institutions
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	45,825	51,874
2019	23,757	135,135
2018	131,932	241,418
2017	211,445	24,097
2016	3	84,244
Prior to 2016	143,717	60,281
Revolving loan	125,078	162,622
Total	681,757	759,671
Financing Receivables Not Impaired | Normal obligors | Domestic | Corporate | Large Companies
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	12,236,438	14,351,596
2019	6,640,211	6,173,182
2018	5,049,408	6,884,219
2017	4,535,083	2,384,565
2016	1,678,591	2,105,541
Prior to 2016	3,378,926	2,256,613
Revolving loan	7,155,041	6,819,851
Total	40,673,698	40,975,567
Financing Receivables Not Impaired | Normal obligors | Domestic | Corporate | Small And Medium Sized Companies
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	540,315	633,438
2019	396,611	463,744
2018	376,056	397,656
2017	283,061	224,791
2016	170,952	205,687
Prior to 2016	494,420	502,707
Revolving loan	547,726	518,612
Total	2,809,141	2,946,635
Financing Receivables Not Impaired | Normal obligors | Foreign | Soverign
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	278,373	96,177
2019	6,856	78,727
2018	33,225	26,569
2017	15,194	157,256
2016	174,298	0
Prior to 2016	3,079	4,474
Revolving loan	74,923	69,320
Total	585,948	432,523
Financing Receivables Not Impaired | Normal obligors | Foreign | Banks and other financial institutions
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	1,003,709	1,030,080
2019	254,232	317,635
2018	150,505	275,695
2017	224,571	18,272
2016	12,041	1,497
Prior to 2016	709	3,105
Revolving loan	120,088	25,145
Total	1,765,855	1,671,429
Financing Receivables Not Impaired | Normal obligors | Foreign | Corporate
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	14,087,409	12,813,813
2019	3,571,416	4,614,310
2018	3,236,191	2,558,432
2017	1,392,231	922,526
2016	550,082	655,823
Prior to 2016	1,228,924	1,143,658
Revolving loan	5,906,045	4,501,155
Total	29,972,298	27,209,717
Financing Receivables Not Impaired | Normal obligors | Foreign | Retail
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	2,403	2,100
2019	1,774	2,342
2018	1,858	1,468
2017	1,013	1,034
2016	532	1,074
Prior to 2016	3,089	1,401
Revolving loan	15	18
Total	10,684	9,437
Financing Receivables Not Impaired | Watch obligors | Domestic | Soverign
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	3,933	4,312
2019	4,205	3,594
2018	859	2,164
2017	366	635
2016	113	31
Prior to 2016	0	0
Revolving loan	0	0
Total	9,476	10,736
Financing Receivables Not Impaired | Watch obligors | Domestic | Banks and other financial institutions
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	0	0
2019	0	0
2018	0	0
2017	0	0
2016	0	0
Prior to 2016	0	0
Revolving loan	0	0
Total	0	0
Financing Receivables Not Impaired | Watch obligors | Domestic | Corporate | Large Companies
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	145,167	151,406
2019	69,404	86,390
2018	71,937	86,199
2017	66,122	61,785
2016	40,205	40,907
Prior to 2016	50,499	35,681
Revolving loan	127,319	128,363
Total	570,653	590,731
Financing Receivables Not Impaired | Watch obligors | Domestic | Corporate | Small And Medium Sized Companies
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	44,488	62,300
2019	31,196	24,245
2018	29,597	30,007
2017	31,919	13,547
2016	12,231	13,536
Prior to 2016	32,511	24,430
Revolving loan	25,277	29,041
Total	207,219	197,106
Financing Receivables Not Impaired | Watch obligors | Foreign | Soverign
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	0	0
2019	0	0
2018	0	0
2017	0	0
2016	0	0
Prior to 2016	0	20,118
Revolving loan	0	0
Total	0	20,118
Financing Receivables Not Impaired | Watch obligors | Foreign | Banks and other financial institutions
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	5,544	6,341
2019	0	0
2018	0	78
2017	0	0
2016	0	4,774
Prior to 2016	0	0
Revolving loan	0	0
Total	5,544	11,193
Financing Receivables Not Impaired | Watch obligors | Foreign | Corporate
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	316,387	196,054
2019	179,555	36,915
2018	73,656	72,529
2017	55,876	54,514
2016	28,325	894
Prior to 2016	25,384	25,009
Revolving loan	122,410	127,553
Total	801,593	513,468
Financing Receivables Not Impaired | Watch obligors | Foreign | Retail
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	0	0
2019	0	0
2018	37	0
2017	0	14
2016	0	0
Prior to 2016	13	13
Revolving loan	0	0
Total	50	27
Financing Receivables Not Impaired | Non Accrual Loans | Domestic | Soverign
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	0	0
2019	0	0
2018	0	0
2017	0	0
2016	0	0
Prior to 2016	0	0
Revolving loan	0	0
Total	0	0
Financing Receivables Not Impaired | Non Accrual Loans | Domestic | Banks and other financial institutions
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	0	0
2019	0	0
2018	0	0
2017	0	0
2016	0	0
Prior to 2016	0	0
Revolving loan	0	0
Total	0	0
Financing Receivables Not Impaired | Non Accrual Loans | Domestic | Corporate | Large Companies
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	60,525	219,111
2019	100,975	196,945
2018	201,375	38,490
2017	44,919	129,066
2016	135,777	28,650
Prior to 2016	77,602	9,547
Revolving loan	178,416	194,607
Total	799,589	816,416
Financing Receivables Not Impaired | Non Accrual Loans | Domestic | Corporate | Small And Medium Sized Companies
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	17,866	78,238
2019	20,110	10,794
2018	14,434	7,341
2017	10,817	5,168
2016	7,081	3,154
Prior to 2016	38,171	8,852
Revolving loan	32,081	28,853
Total	140,560	142,400
Financing Receivables Not Impaired | Non Accrual Loans | Foreign | Soverign
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	0	0
2019	0	710
2018	643	0
2017	0	0
2016	0	0
Prior to 2016	0	0
Revolving loan	0	0
Total	643	710
Financing Receivables Not Impaired | Non Accrual Loans | Foreign | Banks and other financial institutions
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	837	0
2019	0	0
2018	0	0
2017	0	0
2016	0	0
Prior to 2016	0	0
Revolving loan	0	0
Total	837	0
Financing Receivables Not Impaired | Non Accrual Loans | Foreign | Corporate
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	35,801	61,657
2019	1,622	29,657
2018	13,743	12,547
2017	17,181	3,034
2016	14,743	4,417
Prior to 2016	22,639	17,394
Revolving loan	9,745	14,580
Total	115,474	143,286
Financing Receivables Not Impaired | Non Accrual Loans | Foreign | Retail
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	0	0
2019	0	0
2018	0	0
2017	0	0
2016	0	0
Prior to 2016	0	0
Revolving loan	0	0
Total	¥ 0	¥ 0

Loans - Credit Quality Inform_2

Loans - Credit Quality Information of Loans Based on MHFG Group's Internal Rating System (Parenthetical) (Detail) - JPY (¥) ¥ in Millions	Mar. 31, 2022	Mar. 31, 2021
Financing Receivables Impaired [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Direct Financing Lease, Lease Receivable	¥ 216,463	¥ 221,908

Loans - Impaired Loans Informat

Loans - Impaired Loans Information (Detail) - JPY (¥) ¥ in Millions	12 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Financing Receivable, Nonaccrual [Line Items]
Nonaccrual loans with an allowance	¥ 1,082,154	¥ 1,113,550
Nonaccrual loans without an allowance	85,974	110,731
Total nonaccrual loans	1,168,128	1,224,281
Interest income recognized	14,360	19,110
Domestic
Financing Receivable, Nonaccrual [Line Items]
Nonaccrual loans with an allowance	971,870	996,250
Nonaccrual loans without an allowance	79,304	84,035
Total nonaccrual loans	1,051,174	1,080,285
Interest income recognized	12,891	16,688
Domestic | Retail Rating [Member] | Housing Loan
Financing Receivable, Nonaccrual [Line Items]
Nonaccrual loans with an allowance	26,812	37,006
Nonaccrual loans without an allowance	22,380	25,563
Total nonaccrual loans	49,192	62,569
Interest income recognized	946	1,073
Domestic | Retail Rating [Member] | Other
Financing Receivable, Nonaccrual [Line Items]
Nonaccrual loans with an allowance	40,155	37,884
Nonaccrual loans without an allowance	21,678	21,016
Total nonaccrual loans	61,833	58,900
Interest income recognized	819	806
Domestic | Large Companies [Member] | Corporate Rating Member
Financing Receivable, Nonaccrual [Line Items]
Nonaccrual loans with an allowance	783,305	800,329
Nonaccrual loans without an allowance	16,284	16,087
Total nonaccrual loans	799,589	816,416
Interest income recognized	9,426	13,050
Domestic | Small And Medium Sized Companies [Member] | Corporate Rating Member
Financing Receivable, Nonaccrual [Line Items]
Nonaccrual loans with an allowance	121,598	121,031
Nonaccrual loans without an allowance	18,962	21,369
Total nonaccrual loans	140,560	142,400
Interest income recognized	1,700	1,759
Foreign
Financing Receivable, Nonaccrual [Line Items]
Nonaccrual loans with an allowance	110,284	117,300
Nonaccrual loans without an allowance	6,670	26,696
Total nonaccrual loans	116,954	143,996
Interest income recognized	¥ 1,469	¥ 2,422

Loans - Troubled Debt Restructu

Loans - Troubled Debt Restructurings Entered Modified Periods by Type of Concession Granted (Detail) - JPY (¥) ¥ in Millions	12 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Financing Receivable, Modifications [Line Items]
Loan forgiveness or debt to equity swaps Recorded investment	¥ 5,849	¥ 2,614
Loan forgiveness or debt to equity swaps charge-offs	22,757	4,545
Interest rate reduction and/or postponement of principal and/or interest	829,969	926,580
Domestic
Financing Receivable, Modifications [Line Items]
Loan forgiveness or debt to equity swaps Recorded investment	5,849	0
Loan forgiveness or debt to equity swaps charge-offs	22,757	160
Interest rate reduction and/or postponement of principal and/or interest	767,318	763,431
Domestic | Housing Loan | Retail
Financing Receivable, Modifications [Line Items]
Loan forgiveness or debt to equity swaps Recorded investment	0	0
Loan forgiveness or debt to equity swaps charge-offs	0	0
Interest rate reduction and/or postponement of principal and/or interest	7,897	21,548
Domestic | Other | Retail
Financing Receivable, Modifications [Line Items]
Loan forgiveness or debt to equity swaps Recorded investment	0	0
Loan forgiveness or debt to equity swaps charge-offs	0	0
Interest rate reduction and/or postponement of principal and/or interest	21,749	20,604
Domestic | Large Companies | Corporate
Financing Receivable, Modifications [Line Items]
Loan forgiveness or debt to equity swaps Recorded investment	5,849	0
Loan forgiveness or debt to equity swaps charge-offs	22,757	160
Interest rate reduction and/or postponement of principal and/or interest	612,569	597,281
Domestic | Small And Medium Sized Companies | Corporate
Financing Receivable, Modifications [Line Items]
Loan forgiveness or debt to equity swaps Recorded investment	0	0
Loan forgiveness or debt to equity swaps charge-offs	0	0
Interest rate reduction and/or postponement of principal and/or interest	125,103	120,798
Domestic | Banks and other financial institutions
Financing Receivable, Modifications [Line Items]
Loan forgiveness or debt to equity swaps Recorded investment		0
Loan forgiveness or debt to equity swaps charge-offs		0
Interest rate reduction and/or postponement of principal and/or interest		3,200
Foreign
Financing Receivable, Modifications [Line Items]
Loan forgiveness or debt to equity swaps Recorded investment	0	2,614
Loan forgiveness or debt to equity swaps charge-offs	0	4,385
Interest rate reduction and/or postponement of principal and/or interest	¥ 62,651	¥ 163,149

Loans - Payment Defaults Occurr

Loans - Payment Defaults Occurred During Periods with Respect to Loans Modified as Troubled Debt Restructurings within Previous Six Months (Detail) - JPY (¥) ¥ in Millions	12 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Financing Receivable, Modifications [Line Items]
Recorded investment	¥ 26,672	¥ 66,375
Domestic
Financing Receivable, Modifications [Line Items]
Recorded investment	12,546	19,136
Domestic | Corporate | Large companies
Financing Receivable, Modifications [Line Items]
Recorded investment	7,831	10,590
Domestic | Corporate | Small and medium sized companies
Financing Receivable, Modifications [Line Items]
Recorded investment	2,777	5,603
Domestic | Retail | Housing Loan
Financing Receivable, Modifications [Line Items]
Recorded investment	938	810
Domestic | Retail | Other
Financing Receivable, Modifications [Line Items]
Recorded investment	1,000	2,133
Foreign
Financing Receivable, Modifications [Line Items]
Recorded investment	¥ 14,126	¥ 47,239

Loans - Age Analysis of Past Du

Loans - Age Analysis of Past Due Loans (Detail) - JPY (¥) ¥ in Millions	Mar. 31, 2022	Mar. 31, 2021
30-59 Days Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Notes receivable gross	¥ 20,651	¥ 17,602
30-59 Days Past Due | Domestic
Accounts, Notes, Loans and Financing Receivable [Line Items]
Notes receivable gross	20,651	17,602
30-59 Days Past Due | Domestic | Soverign
Accounts, Notes, Loans and Financing Receivable [Line Items]
Notes receivable gross	0	0
30-59 Days Past Due | Domestic | Corporate | Large companies
Accounts, Notes, Loans and Financing Receivable [Line Items]
Notes receivable gross	323	1,275
30-59 Days Past Due | Domestic | Corporate | Small and medium sized companies
Accounts, Notes, Loans and Financing Receivable [Line Items]
Notes receivable gross	693	1,386
30-59 Days Past Due | Domestic | Retail | Housing Loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Notes receivable gross	15,181	9,776
30-59 Days Past Due | Domestic | Retail | Other
Accounts, Notes, Loans and Financing Receivable [Line Items]
Notes receivable gross	4,454	5,165
30-59 Days Past Due | Domestic | Banks and other financial institutions
Accounts, Notes, Loans and Financing Receivable [Line Items]
Notes receivable gross	0	0
30-59 Days Past Due | Foreign
Accounts, Notes, Loans and Financing Receivable [Line Items]
Notes receivable gross	0	0
60-89 Days Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Notes receivable gross	10,326	20,309
60-89 Days Past Due | Domestic
Accounts, Notes, Loans and Financing Receivable [Line Items]
Notes receivable gross	10,326	12,832
60-89 Days Past Due | Domestic | Soverign
Accounts, Notes, Loans and Financing Receivable [Line Items]
Notes receivable gross	0	0
60-89 Days Past Due | Domestic | Corporate | Large companies
Accounts, Notes, Loans and Financing Receivable [Line Items]
Notes receivable gross	291	4,607
60-89 Days Past Due | Domestic | Corporate | Small and medium sized companies
Accounts, Notes, Loans and Financing Receivable [Line Items]
Notes receivable gross	641	0
60-89 Days Past Due | Domestic | Retail | Housing Loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Notes receivable gross	8,326	7,102
60-89 Days Past Due | Domestic | Retail | Other
Accounts, Notes, Loans and Financing Receivable [Line Items]
Notes receivable gross	1,068	1,123
60-89 Days Past Due | Domestic | Banks and other financial institutions
Accounts, Notes, Loans and Financing Receivable [Line Items]
Notes receivable gross	0	0
60-89 Days Past Due | Foreign
Accounts, Notes, Loans and Financing Receivable [Line Items]
Notes receivable gross	0	7,477
90 Days or More Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Notes receivable gross	94,018	100,636
90 Days or More Past Due | Domestic
Accounts, Notes, Loans and Financing Receivable [Line Items]
Notes receivable gross	65,202	69,841
90 Days or More Past Due | Domestic | Soverign
Accounts, Notes, Loans and Financing Receivable [Line Items]
Notes receivable gross	0	0
90 Days or More Past Due | Domestic | Corporate | Large companies
Accounts, Notes, Loans and Financing Receivable [Line Items]
Notes receivable gross	27,275	27,387
90 Days or More Past Due | Domestic | Corporate | Small and medium sized companies
Accounts, Notes, Loans and Financing Receivable [Line Items]
Notes receivable gross	10,370	9,185
90 Days or More Past Due | Domestic | Retail | Housing Loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Notes receivable gross	16,548	21,257
90 Days or More Past Due | Domestic | Retail | Other
Accounts, Notes, Loans and Financing Receivable [Line Items]
Notes receivable gross	11,009	12,012
90 Days or More Past Due | Domestic | Banks and other financial institutions
Accounts, Notes, Loans and Financing Receivable [Line Items]
Notes receivable gross	0	0
90 Days or More Past Due | Foreign
Accounts, Notes, Loans and Financing Receivable [Line Items]
Notes receivable gross	28,816	30,795
Total Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Notes receivable gross	124,995	138,547
Total Past Due | Domestic
Accounts, Notes, Loans and Financing Receivable [Line Items]
Notes receivable gross	96,179	100,275
Total Past Due | Domestic | Soverign
Accounts, Notes, Loans and Financing Receivable [Line Items]
Notes receivable gross	0	0
Total Past Due | Domestic | Corporate | Large companies
Accounts, Notes, Loans and Financing Receivable [Line Items]
Notes receivable gross	27,889	33,269
Total Past Due | Domestic | Corporate | Small and medium sized companies
Accounts, Notes, Loans and Financing Receivable [Line Items]
Notes receivable gross	11,704	10,571
Total Past Due | Domestic | Retail | Housing Loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Notes receivable gross	40,055	38,135
Total Past Due | Domestic | Retail | Other
Accounts, Notes, Loans and Financing Receivable [Line Items]
Notes receivable gross	16,531	18,300
Total Past Due | Domestic | Banks and other financial institutions
Accounts, Notes, Loans and Financing Receivable [Line Items]
Notes receivable gross	0	0
Total Past Due | Foreign
Accounts, Notes, Loans and Financing Receivable [Line Items]
Notes receivable gross	28,816	38,272
Current
Accounts, Notes, Loans and Financing Receivable [Line Items]
Notes receivable gross	90,165,588	88,442,320
Current | Domestic
Accounts, Notes, Loans and Financing Receivable [Line Items]
Notes receivable gross	56,935,478	58,468,684
Current | Domestic | Soverign
Accounts, Notes, Loans and Financing Receivable [Line Items]
Notes receivable gross	1,660,345	2,235,890
Current | Domestic | Corporate | Large companies
Accounts, Notes, Loans and Financing Receivable [Line Items]
Notes receivable gross	42,016,051	42,349,445
Current | Domestic | Corporate | Small and medium sized companies
Accounts, Notes, Loans and Financing Receivable [Line Items]
Notes receivable gross	3,145,216	3,275,570
Current | Domestic | Retail | Housing Loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Notes receivable gross	7,741,465	7,975,654
Current | Domestic | Retail | Other
Accounts, Notes, Loans and Financing Receivable [Line Items]
Notes receivable gross	1,690,644	1,872,454
Current | Domestic | Banks and other financial institutions
Accounts, Notes, Loans and Financing Receivable [Line Items]
Notes receivable gross	681,757	759,671
Current | Foreign
Accounts, Notes, Loans and Financing Receivable [Line Items]
Notes receivable gross	33,230,110	29,973,636
Total
Accounts, Notes, Loans and Financing Receivable [Line Items]
Notes receivable gross	90,290,583	88,580,867
Total | Domestic
Accounts, Notes, Loans and Financing Receivable [Line Items]
Notes receivable gross	57,031,657	58,568,959
Total | Domestic | Soverign
Accounts, Notes, Loans and Financing Receivable [Line Items]
Notes receivable gross	1,660,345	2,235,890
Total | Domestic | Corporate | Large companies
Accounts, Notes, Loans and Financing Receivable [Line Items]
Notes receivable gross	42,043,940	42,382,714
Total | Domestic | Corporate | Small and medium sized companies
Accounts, Notes, Loans and Financing Receivable [Line Items]
Notes receivable gross	3,156,920	3,286,141
Total | Domestic | Retail | Housing Loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Notes receivable gross	7,781,520	8,013,789
Total | Domestic | Retail | Other
Accounts, Notes, Loans and Financing Receivable [Line Items]
Notes receivable gross	1,707,175	1,890,754
Total | Domestic | Banks and other financial institutions
Accounts, Notes, Loans and Financing Receivable [Line Items]
Notes receivable gross	681,757	759,671
Total | Foreign
Accounts, Notes, Loans and Financing Receivable [Line Items]
Notes receivable gross	¥ 33,258,926	¥ 30,011,908

Allowance for Credit Losses o_3

Allowance for Credit Losses on Loans (Changes in Allowance for Loan Losses, Allowance for Loan Losses and Loans Outstanding Disaggregated on Basis of Impairment Method, by Portfolio Segment) (Detail) - JPY (¥) ¥ in Millions	12 Months Ended
	Mar. 31, 2022	Mar. 31, 2021	Mar. 31, 2020
Accounts, Notes, Loans and Financing Receivable [Line Items]
Balance at beginning of fiscal year	¥ 650,849	¥ 440,855	¥ 307,201
Provision (credit) for credit losses on loans	187,599	112,776	156,200
Charge-offs	(59,840)	(78,801)	(44,358)
Recoveries	18,754	13,935	27,916
Net charge-offs	(41,086)	(64,866)	(16,442)
Others	12,455	6,329	(6,104)
Balance at end of fiscal year	809,817	650,849	440,855
Cumulative effect of change in accounting principles
Accounts, Notes, Loans and Financing Receivable [Line Items]
Balance at beginning of fiscal year		155,755
Balance at end of fiscal year			155,755
Cumulative effect, period of adoption, adjusted balance
Accounts, Notes, Loans and Financing Receivable [Line Items]
Balance at beginning of fiscal year		596,610
Balance at end of fiscal year			596,610
Corporate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Balance at beginning of fiscal year	562,470	413,026	277,955
Provision (credit) for credit losses on loans	194,022	124,086	149,915
Charge-offs	(55,662)	(72,212)	(35,021)
Recoveries	17,912	13,047	26,338
Net charge-offs	(37,750)	(59,165)	(8,683)
Others	12,500	7,009	(6,161)
Balance at end of fiscal year	731,242	562,470	413,026
Corporate | Cumulative effect of change in accounting principles
Accounts, Notes, Loans and Financing Receivable [Line Items]
Balance at beginning of fiscal year		77,514
Balance at end of fiscal year			77,514
Corporate | Cumulative effect, period of adoption, adjusted balance
Accounts, Notes, Loans and Financing Receivable [Line Items]
Balance at beginning of fiscal year		490,540
Balance at end of fiscal year			490,540
Retail
Accounts, Notes, Loans and Financing Receivable [Line Items]
Balance at beginning of fiscal year	88,379	27,829	29,246
Provision (credit) for credit losses on loans	(6,423)	(11,310)	6,285
Charge-offs	(4,178)	(6,589)	(9,337)
Recoveries	842	888	1,578
Net charge-offs	(3,336)	(5,701)	(7,759)
Others	(45)	(680)	57
Balance at end of fiscal year	¥ 78,575	88,379	27,829
Retail | Cumulative effect of change in accounting principles
Accounts, Notes, Loans and Financing Receivable [Line Items]
Balance at beginning of fiscal year		78,241
Balance at end of fiscal year			78,241
Retail | Cumulative effect, period of adoption, adjusted balance
Accounts, Notes, Loans and Financing Receivable [Line Items]
Balance at beginning of fiscal year		¥ 106,070
Balance at end of fiscal year			¥ 106,070

Premises and equipment-Summary

Premises and equipment-Summary of Premises and Equipment (Detail) - JPY (¥) ¥ in Millions	Mar. 31, 2022	Mar. 31, 2021
Property, Plant and Equipment [Line Items]
Premises and equipment, gross	¥ 3,286,694	¥ 3,338,783
Less: Accumulated depreciation and amortization	1,582,627	1,527,325
Premises and equipment—net	1,704,067	1,811,458
Land
Property, Plant and Equipment [Line Items]
Premises and equipment, gross	571,837	569,337
Buildings
Property, Plant and Equipment [Line Items]
Premises and equipment, gross	737,440	737,144
Equipment and furniture
Property, Plant and Equipment [Line Items]
Premises and equipment, gross	373,825	414,201
Leasehold improvements
Property, Plant and Equipment [Line Items]
Premises and equipment, gross	208,820	222,296
Construction in Progress
Property, Plant and Equipment [Line Items]
Premises and equipment, gross	21,737	23,441
Software
Property, Plant and Equipment [Line Items]
Premises and equipment, gross	¥ 1,373,035	¥ 1,372,364

Premises and Equipment - Additi

Premises and Equipment - Additional Information (Detail) - JPY (¥) ¥ in Millions	12 Months Ended
	Mar. 31, 2022	Mar. 31, 2021	Mar. 31, 2020
Property, Plant and Equipment [Line Items]
Impairment losses	¥ 13,500	¥ 7,101	¥ 13,490
Depreciation and amortization	220,436	223,164	234,457
Global Corporate Company or Retail and Business Banking Company
Property, Plant and Equipment [Line Items]
Impairment losses on real estate		2,275
Entity Wide Software
Property, Plant and Equipment [Line Items]
Impairment losses		3,397	6,774
Impairment losses on real estate	12,976
General and Administrative expenses
Property, Plant and Equipment [Line Items]
Impairment losses	433	3,872	6,813
Occupancy expenses
Property, Plant and Equipment [Line Items]
Impairment losses	¥ 13,067	¥ 3,229	6,677
Retail and Business Banking Company
Property, Plant and Equipment [Line Items]
Impairment losses on real estate			¥ 5,587

Goodwill and Intangible Asset_2

Goodwill and Intangible Assets (Changes in Goodwill) (Detail) - JPY (¥) ¥ in Millions	12 Months Ended
	Mar. 31, 2022	Mar. 31, 2021	Mar. 31, 2020
Goodwill [Line Items]
Balance at beginning of fiscal year	¥ 92,695	¥ 92,997	¥ 95,151
Impairment losses recognized	0	(302)	(2,155)
Foreign exchange translation	0	0	1
Balance at end of fiscal year	92,695	92,695	92,997
Gross amount of goodwill	161,993	167,552	169,313
Accumulated impairment losses	¥ 69,298	¥ 74,857	¥ 76,316

Goodwill and Intangible Asset_3

Goodwill and Intangible Assets (Gross Carrying Amount, Accumulated Amortization and Net Carrying Amount of Intangible Assets) (Detail) - JPY (¥) ¥ in Millions		Mar. 31, 2022	Mar. 31, 2021
Intangible Assets by Major Class [Line Items]
Gross carrying amount		¥ 128,447	¥ 128,408
Gross carrying amount		8,006	8,309
Net carrying amount		8,006	8,309
Gross carrying amount		136,453	136,717
Accumulated amortization		88,514	80,596
Net carrying amount		39,933	47,812
Net carrying amount		47,939	56,121
Customer relationships
Intangible Assets by Major Class [Line Items]
Gross carrying amount	[1]	126,979	126,979
Accumulated amortization	[1]	87,277	79,362
Net carrying amount	[1]	39,702	47,617
Other
Intangible Assets by Major Class [Line Items]
Gross carrying amount		1,468	1,429
Accumulated amortization		1,237	1,234
Net carrying amount		¥ 231	¥ 195
[1]Customer relationships were acquired in connection with the merger of MHSC and Shinko on May 7, 2009 and the integration among asset management companies on October 1, 2016. See Note 1 “Basis of presentation and summary of significant accounting policies” for further information.

Goodwill and Intangible Asset_4

Goodwill and Intangible Assets - Additional Information (Detail) - JPY (¥) ¥ in Millions	12 Months Ended
	Mar. 31, 2022	Mar. 31, 2021	Mar. 31, 2020
Goodwill and Intangible Assets Disclosure [Line Items]
Intangible assets amortization expense recognized	¥ 7,961	¥ 8,513	¥ 9,267

Goodwill and Intangible Asset_5

Goodwill and Intangible Assets (Estimated Aggregate Amortization Expense in Respect of Intangible Assets) (Detail) ¥ in Millions	Mar. 31, 2022 JPY (¥)
Finite-Lived Intangible Assets [Line Items]
2023	¥ 7,174
2024	6,660
2025	6,149
2026	5,645
2027	¥ 5,138

Pledged Assets and Collateral_2

Pledged Assets and Collateral (Amounts Pledged as Collateral for Borrowings and for Other Purposes) (Detail) - JPY (¥) ¥ in Billions	Mar. 31, 2022	Mar. 31, 2021
Financial Instruments Owned and Pledged as Collateral [Line Items]
Interest-bearing deposits in other banks	¥ 75	¥ 71
Trading account assets	5,426	7,424
Investments	8,091	5,573
Loans	9,056	10,417
Other assets	3,023	2,291
Total	¥ 25,671	¥ 25,776

Pledged Assets and Collateral_3

Pledged Assets and Collateral (Associated Liabilities Collateralized by Pledged Assets) (Detail) - JPY (¥) ¥ in Billions	Mar. 31, 2022	Mar. 31, 2021
Assets and Associated Liabilities of Transfers Accounted for as Secured Borrowings [Line Items]
Deposits	¥ 910	¥ 764
Payables under repurchase agreements	5,864	6,334
Payables under securities lending transactions	645	1,185
Other short-term borrowings	5,113	6,272
Long-term debt	542	192
Total	¥ 13,074	¥ 14,747

Pledged Assets and Collateral -

Pledged Assets and Collateral - Additional Information (Detail) - JPY (¥) ¥ in Billions	Mar. 31, 2022	Mar. 31, 2021
Assets that Continue to be Recognized, Securitized or Asset-backed Financing Arrangement Assets and any Other Financial Assets Managed Together [Line Items]
Reserve funds maintained with the BOJ	¥ 48,897	¥ 46,346
Reserve funds requires to be maintained by MHFG Group	1,678	1,617
Fair value collateral received that can be sold or repledged	16,632	13,882
Fair value collateral received that can be sold or repledged, value of collateral sold or repledged	¥ 14,865	¥ 12,583

Deposits (Estimated amounts Of

Deposits (Estimated amounts Of Uninsured Time Deposits And Certificates Of Deposit Issued By Domestic And Foreign Offices) (Detail) - JPY (¥) ¥ in Millions	Mar. 31, 2022	Mar. 31, 2021
Domestic
Deposits From Banking Clients [Line Items]
Domestic deposit	¥ 20,885	¥ 22,603
Foreign
Deposits From Banking Clients [Line Items]
Domestic deposit	24,926	21,581
Time deposits | Domestic
Deposits From Banking Clients [Line Items]
Domestic deposit	10,437	12,004
Time deposits | Foreign
Deposits From Banking Clients [Line Items]
Domestic deposit	18,505	14,987
Certificates of deposit | Domestic
Deposits From Banking Clients [Line Items]
Domestic deposit	10,448	10,599
Certificates of deposit | Foreign
Deposits From Banking Clients [Line Items]
Domestic deposit	¥ 6,421	¥ 6,594

Deposits - Additional Informati

Deposits - Additional Information (Detail) - JPY (¥) ¥ in Billions	Mar. 31, 2022	Mar. 31, 2021
Deposits From Banking Clients [Line Items]
Aggregate amount of demand deposits in overdraft status that have been reclassified as loan balances	¥ 585	¥ 627

Deposits (Balance and Remaining

Deposits (Balance and Remaining Maturities of Time Deposits and Certificates of Deposit Issued by Domestic and Foreign Offices) (Detail) ¥ in Millions	Mar. 31, 2022 JPY (¥)
Deposits From Banking Clients [Line Items]
Total	¥ 53,714,176
Bank Time Deposits Liabilities Domestic
Deposits From Banking Clients [Line Items]
Due in one year or less	15,082,821
Due after one year through two years	1,374,855
Due after two years through three years	1,106,825
Due after three years through four years	306,455
Due after four years through five years	281,141
Due after five years	188,260
Total	18,340,357
Certificates Of Deposit Liabilities Domestic
Deposits From Banking Clients [Line Items]
Due in one year or less	10,224,412
Due after one year through two years	222,560
Due after two years through three years	0
Due after three years through four years	500
Due after four years through five years	0
Due after five years	0
Total	10,447,472
Bank Time Deposits Liabilities Foreign
Deposits From Banking Clients [Line Items]
Due in one year or less	18,439,713
Due after one year through two years	18,847
Due after two years through three years	25,388
Due after three years through four years	19,581
Due after four years through five years	1,359
Due after five years	0
Total	18,504,888
Certificates Of Deposit Liabilities Foreign
Deposits From Banking Clients [Line Items]
Due in one year or less	6,065,429
Due after one year through two years	78,816
Due after two years through three years	277,214
Due after three years through four years	0
Due after four years through five years	0
Due after five years	0
Total	6,421,459
Time deposits
Deposits From Banking Clients [Line Items]
Total	36,845,245
Certificates of deposit
Deposits From Banking Clients [Line Items]
Total	16,868,931
Domestic
Deposits From Banking Clients [Line Items]
Due in one year or less	25,307,233
Due after one year through two years	1,597,415
Due after two years through three years	1,106,825
Due after three years through four years	306,955
Due after four years through five years	281,141
Due after five years	188,260
Total	28,787,829
Foreign
Deposits From Banking Clients [Line Items]
Due in one year or less	24,505,142
Due after one year through two years	97,663
Due after two years through three years	302,602
Due after three years through four years	19,581
Due after four years through five years	1,359
Due after five years	0
Total	¥ 24,926,347

Short-Term Borrowings and Lon_3

Short-Term Borrowings and Long-Term Debt (Details of Other Short-Term Borrowings) (Detail) - JPY (¥) ¥ in Millions		Mar. 31, 2022	Mar. 31, 2021
Short-term Debt [Line Items]
Borrowings from the Bank of Japan		¥ 5,105,225	¥ 6,253,123
Other		148,518	271,675
Total		7,566,771	9,085,912
Mizuho Financial Group Inc
Short-term Debt [Line Items]
Commercial paper and short-term notes issued	[1],[2]	2,266,360	2,528,568
Consolidated VIEs
Short-term Debt [Line Items]
Commercial paper and short-term notes issued		46,668	32,546
Total		¥ 53,668	¥ 36,546
[1]Short-term notes are issued under the laws of Japan in the form of commercial paper.[2]The amounts of commercial paper and short-term notes issued by MHFG’s subsidiaries were ¥2,105,068million and ¥423,500 million, respectively, at March 31, 2021, and ¥1,775,860 million and ¥490,500 million, respectively, at March 31, 2022.

Short-Term Borrowings and Lon_4

Short-Term Borrowings and Long-Term Debt (Details of Other Short-Term Borrowings) (Parenthetical) (Detail) - Mizuho Financial Group Inc - JPY (¥) ¥ in Millions	Mar. 31, 2022	Mar. 31, 2021
Short-term Debt [Line Items]
Commercial paper	¥ 1,775,860	¥ 2,105,068
Short-term notes	¥ 490,500	¥ 423,500

Short-Term Borrowings and Lon_5

Short-Term Borrowings and Long-Term Debt (Long-Term Debt with Original Maturities of More than One Year) (Detail) - JPY (¥) ¥ in Millions	Mar. 31, 2022	Mar. 31, 2021
Debt Instrument [Line Items]
Obligations under finance leases	¥ 4,621	¥ 9,170
Finance Lease, Liability, Statement of Financial Position [Extensible Enumeration]	Obligations under finance leases	Obligations under finance leases
Loan participation borrowings	¥ 220,312	¥ 169,069
Senior borrowings and bonds	8,600,493	7,494,512
Subordinated borrowings and bonds	3,752,790	4,033,720
Total	¥ 12,578,216	¥ 11,706,471

Short-Term Borrowings and Lon_6

Short-Term Borrowings and Long-Term Debt (Interest Rates and Maturities of Senior Borrowings and Bonds, and Subordinated Borrowings and Bonds) (Detail) - JPY (¥) ¥ in Millions		12 Months Ended
		Mar. 31, 2022	Mar. 31, 2021
Debt Instrument [Line Items]
Borrowings and bonds		¥ 12,353,283	¥ 11,528,232
Senior borrowings and bonds
Debt Instrument [Line Items]
Borrowings and bonds		8,600,493	7,494,512
Senior borrowings and bonds | Fixed Rate | Denominated in Japanese yen
Debt Instrument [Line Items]
Borrowings and bonds		1,032,194	547,133
Senior borrowings and bonds | Fixed Rate | Denominated in U.S. dollars
Debt Instrument [Line Items]
Borrowings and bonds		3,581,901	3,275,076
Senior borrowings and bonds | Fixed Rate | Denominated in other currencies
Debt Instrument [Line Items]
Borrowings and bonds		1,223,991	838,247
Senior borrowings and bonds | Floating Rate | Denominated in Japanese yen
Debt Instrument [Line Items]
Borrowings and bonds		582,430	584,606
Senior borrowings and bonds | Floating Rate | Denominated in U.S. dollars
Debt Instrument [Line Items]
Borrowings and bonds		2,001,616	2,035,844
Senior borrowings and bonds | Floating Rate | Denominated in other currencies
Debt Instrument [Line Items]
Borrowings and bonds		178,361	213,606
Subordinated borrowings and bonds
Debt Instrument [Line Items]
Borrowings and bonds		3,752,790	4,033,720
Subordinated borrowings and bonds | Fixed Rate | Denominated in Japanese yen
Debt Instrument [Line Items]
Borrowings and bonds		3,171,343	3,618,520
Subordinated borrowings and bonds | Fixed Rate | Denominated in U.S. dollars
Debt Instrument [Line Items]
Borrowings and bonds		¥ 581,447	¥ 415,200
Minimum [Member] | Senior borrowings and bonds | Fixed Rate | Denominated in Japanese yen
Debt Instrument [Line Items]
Interest rates	[1]	0%
Maturities, Start	[2]	2022-04
Minimum [Member] | Senior borrowings and bonds | Fixed Rate | Denominated in U.S. dollars
Debt Instrument [Line Items]
Interest rates	[1]	0%
Maturities, Start	[2]	2022-04
Minimum [Member] | Senior borrowings and bonds | Fixed Rate | Denominated in other currencies
Debt Instrument [Line Items]
Interest rates	[1]	0%
Maturities, Start	[2]	2022-04
Minimum [Member] | Senior borrowings and bonds | Floating Rate | Denominated in Japanese yen
Debt Instrument [Line Items]
Interest rates	[1]	0%
Maturities, Start	[2]	2022-04
Minimum [Member] | Senior borrowings and bonds | Floating Rate | Denominated in U.S. dollars
Debt Instrument [Line Items]
Interest rates	[1]	0%
Maturities, Start	[2]	2022-04
Minimum [Member] | Senior borrowings and bonds | Floating Rate | Denominated in other currencies
Debt Instrument [Line Items]
Interest rates	[1]	0%
Maturities, Start	[2]	2022-04
Minimum [Member] | Subordinated borrowings and bonds | Fixed Rate | Denominated in Japanese yen
Debt Instrument [Line Items]
Interest rates	[1]	0.39%
Maturities, Start	[2]	2022-06
Minimum [Member] | Subordinated borrowings and bonds | Fixed Rate | Denominated in U.S. dollars
Debt Instrument [Line Items]
Interest rates	[1]	2.56%
Maturities, Start	[2]	2022-07
Maximum [Member] | Senior borrowings and bonds | Fixed Rate | Denominated in Japanese yen
Debt Instrument [Line Items]
Interest rates	[1]	6.20%
Maturities, End	[2]	2051-06
Maximum [Member] | Senior borrowings and bonds | Fixed Rate | Denominated in U.S. dollars
Debt Instrument [Line Items]
Interest rates	[1]	4.55%
Maturities, End	[2]	2048-03
Maximum [Member] | Senior borrowings and bonds | Fixed Rate | Denominated in other currencies
Debt Instrument [Line Items]
Interest rates	[1]	6%
Maturities, End	[2]	2041-05
Maximum [Member] | Senior borrowings and bonds | Floating Rate | Denominated in Japanese yen
Debt Instrument [Line Items]
Interest rates	[1]	52.70%
Maturities, End	[2]	2081-09
Maximum [Member] | Senior borrowings and bonds | Floating Rate | Denominated in U.S. dollars
Debt Instrument [Line Items]
Interest rates	[1]	54.20%
Maturities, End	[2]	2061-12
Maximum [Member] | Senior borrowings and bonds | Floating Rate | Denominated in other currencies
Debt Instrument [Line Items]
Interest rates	[1]	16.70%
Maturities, End	[2]	2041-09
Maximum [Member] | Subordinated borrowings and bonds | Fixed Rate | Denominated in Japanese yen
Debt Instrument [Line Items]
Interest rates	[1]	4.26%
Maximum [Member] | Subordinated borrowings and bonds | Fixed Rate | Denominated in U.S. dollars
Debt Instrument [Line Items]
Interest rates	[1]	4.70%
Maturities, End	[2]	2031-09
[1]The interest rates disclosed reflect the range of contractual rates in effect at March 31, 2022.[2]Maturity information disclosed is the range of maturities at March 31, 2022.

Short-Term Borrowings and Lon_7

Short-Term Borrowings and Long-Term Debt (Contractual Maturities of Long-Term Debt) (Detail) - JPY (¥) ¥ in Millions	Mar. 31, 2022	Mar. 31, 2021
Debt Instrument [Line Items]
2023	¥ 1,776,915
2024	1,119,756
2025	1,600,277
2026	614,659
2027	1,450,956
2028 and thereafter	6,015,653
Total	¥ 12,578,216	¥ 11,706,471

Other Assets and Liabilities (D

Other Assets and Liabilities (Details of Other Assets and Liabilities) (Detail) - JPY (¥) ¥ in Millions		Mar. 31, 2022	Mar. 31, 2021
Other assets:
Receivables from brokers, dealers and customers for securities transactions		¥ 3,049,874	¥ 2,339,902
Other		557,842	393,410
Collateral pledged for derivative transactions		1,549,483	1,088,847
Margins provided for futures contracts		466,531	297,496
Other		1,006,849	939,557
Prepaid pension cost		762,147	999,962
Right-of-use assets	[1]	570,171	611,533
Security deposits		91,766	104,915
Loans held for sale		156,639	29,834
Other		775,940	651,572
Total		8,987,242	7,457,028
Other liabilities:
Payables to brokers, dealers and customers for securities transactions		1,406,965	2,576,887
Other		494,538	403,501
Guaranteed trust principal	[2]	810,776	814,509
Lease liabilities	[1]	¥ 593,339	¥ 636,541
Operating Lease, Liability, Statement of Financial Position [Extensible List]		Lease liabilities	Lease liabilities
Collateral accepted for derivative transactions		¥ 1,075,591	¥ 763,642
Margins accepted for futures contracts		327,883	555,760
Unearned income		113,181	120,521
Other		1,437,949	1,337,397
Total		¥ 6,260,222	¥ 7,208,758
[1]Right-of-use assets and lease liabilities are included in Other assets and Other liabilities, respectively, on the consolidated balance sheets.[2]Guaranteed trust principal, included in All other liabilities in the disclosure about consolidated VIEs in the accompanying balance sheets, is a liability of certain consolidated trust arrangements that meet the definition of a VIE for which the MHFG Group provides guarantees for the repayment of principal. See Note 24 “Variable interest entities and securitizations” for further discussion of the guaranteed principal money trusts.

Preferred Stock (Composition of

Preferred Stock (Composition of Preferred Stock) (Detail) - shares	Mar. 31, 2022	Mar. 31, 2021	Mar. 31, 2020
Class Fourteen Preferred Stock
Class of Stock [Line Items]
Number of shares Authorized	90,000,000	90,000,000	90,000,000
Number of shares Issued	0	0	0
Class Fifteen Preferred Stock
Class of Stock [Line Items]
Number of shares Authorized	90,000,000	90,000,000	90,000,000
Number of shares Issued	0	0	0
Class Sixteen Preferred Stock
Class of Stock [Line Items]
Number of shares Authorized	150,000,000	150,000,000	150,000,000
Number of shares Issued	0	0	0

Common Stock - Summary of Chang

Common Stock - Summary of Changes in Number of Issued Shares of Common Stock (Detail) - shares	12 Months Ended
	Mar. 31, 2022	Mar. 31, 2021	Mar. 31, 2020
Class of Stock [Line Items]
Balance at beginning of fiscal year	2,539,249,894	2,539,249,894	2,539,249,894
Issuance of new shares of common stock due to exercise of stock acquisition rights	0	0	0
Balance at end of fiscal year	2,539,249,894	2,539,249,894	2,539,249,894

Dividends - Additional Informat

Dividends - Additional Information (Detail) ¥ in Millions	12 Months Ended
	Mar. 31, 2022 JPY (¥)
Japan Gaap Schedule Of Compliance With Regulatory Capital Requirements Under Banking Regulations [Line Items]
Capital stock	¥ 2,256,768
Capital surplus	1,196,660
Retained earnings	¥ 2,158,673
Description of dividend payment restrictions	Pursuant to the Companies Act, in making a distribution of retained earnings, an entity must set aside in its legal reserve an amount equal to one-tenth of the amount of retained earnings so distributed, until its legal reserve reaches one-quarter of its capital stock.
Legal reserve	¥ 1,201,010
Maximum amount available for dividends under Company Law and the Banking Law	2,147,566
Japan Gaap Additional PaidIn Capital [Member]
Japan Gaap Schedule Of Compliance With Regulatory Capital Requirements Under Banking Regulations [Line Items]
Legal reserve	1,196,660
Japan Gaap Retained Earnings [Member]
Japan Gaap Schedule Of Compliance With Regulatory Capital Requirements Under Banking Regulations [Line Items]
Legal reserve	¥ 4,350

Accumulated other comprehensi_3

Accumulated other comprehensive income (loss), net of tax Changes in Each Component of AOCI) (Detail) - JPY (¥) ¥ in Millions		12 Months Ended
		Mar. 31, 2022		Mar. 31, 2021		Mar. 31, 2020
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance at beginning of fiscal year		¥ 9,688,157		¥ 9,175,624
Less: reclassification adjustments for losses (gains) included in net income		(79)
Change during year		126,593		327,108		¥ (172,055)
Balance at end of fiscal year		9,442,231		9,688,157		9,175,624
Accumulated Other Comprehensive Income
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance at beginning of fiscal year	[1]	318,114		(9,494)		164,021
Change during year	[1]	121,998		327,608		(172,463)
Balance at end of fiscal year	[1]	440,112		318,114		(9,494)
Accumulated Other Comprehensive Income | Cumulative effect, period of adoption, adjusted balance
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance at beginning of fiscal year		0	[1]	0		(1,052)	[1],[2]
Balance at beginning of fiscal year, adjusted	[1]	318,114		(9,494)		162,969
Balance at end of fiscal year				0	[1]	0
Net unrealized gains (losses) on available-for-sale securities
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance at beginning of fiscal year		(8,173)		(19,592)		22,019
Unrealized gains (losses) during year		(35,922)		(4,911)		(22,566)
Less: reclassification adjustments for losses (gains) included in net income		19,049		16,330		(19,045)
Change during year		(16,873)		11,419		(41,611)
Balance at end of fiscal year		(25,046)		(8,173)		(19,592)
Foreign currency translation adjustments
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance at beginning of fiscal year		(86,873)		(109,872)		(58,558)
Foreign currency translation adjustments during year		181,722		22,704		(49,888)
Less: reclassification adjustments for losses (gains) included in net income		(745)		295		(374)
Change during year		180,977		22,999		(50,262)
Balance at end of fiscal year		94,104		(86,873)		(109,872)
Foreign currency translation adjustments | Cumulative effect, period of adoption, adjusted balance
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance at beginning of fiscal year	[3]	0		0		(1,052)
Balance at beginning of fiscal year, adjusted		(86,873)		(109,872)		(59,610)
Balance at end of fiscal year	[3]			0		0
Defined benefit plan adjustments
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance at beginning of fiscal year		397,153		69,455		196,446
Unrealized gains (losses) during year		(22,825)		331,668		(122,219)
Less: reclassification adjustments for losses (gains) included in net income		(18,973)		(3,970)		(4,772)
Change during year		(41,798)		327,698		(126,991)
Balance at end of fiscal year		355,355		397,153		69,455
Accumulated Own Credit Risk Adjustment Including Portion Attributable to Noncontrolling Interest
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance at beginning of fiscal year		16,007		50,515		4,114
Unrealized gains (losses) during year		(858)		(30,345)		45,560
Less: reclassification adjustments for losses (gains) included in net income		550		(4,163)		841
Change during year		(308)		(34,508)		46,401
Balance at end of fiscal year		¥ 15,699		¥ 16,007		¥ 50,515
[1]The amounts that have been reclassified out of Accumulated other comprehensive income (loss), net of tax into net income are presented in Note 16 “Accumulated other comprehensive income (loss), net of tax.”[2]These amounts resulted from the adoption of ASU No.2017-12, “Derivatives and Hedging (Topic 815)—Targeted Improvements to Accounting for Hedging Activities.”[3]The MHFG Group adopted ASU No.2017-12, “Derivatives and Hedging (Topic 815)—Targeted Improvements to Accounting for Hedging Activities” (“ASU No.2017-12”) on April 1, 2019 and the ASU No.2017-12 eliminated the separate measurement and reporting of hedge ineffectiveness. Cumulative-effect adjustment to the consolidated balance sheets was recognized upon adoption.

Accumulated other comprehensi_4

Accumulated other comprehensive income (loss), net of tax (Amounts Reclassified Out of Accumulated Other Comprehensive Income into Net Income) (Detail) ¥ in Millions	12 Months Ended
	Mar. 31, 2022 JPY (¥)
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Before tax	¥ (948)	[1]
Tax effect	1,027	[2]
Net of tax before allocation to noncontrolling interests	79
Net of tax attributable to noncontrolling interests	40	[2]
Net of tax attributable to MHFG shareholders	119
Accumulated Net Unrealized Investment Gain (Loss) | Gain (Loss) on Investments
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Before tax	(27,553)	[1]
Tax effect	8,504	[2]
Net of tax before allocation to noncontrolling interests	(19,049)
Net of tax attributable to MHFG shareholders	(19,049)
Accumulated Foreign Currency Adjustments | Gain (Loss) on Investments
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Before tax	745	[1]
Net of tax before allocation to noncontrolling interests	745
Net of tax attributable to MHFG shareholders	745
Accumulated Defined Benefit Plans Adjustment | Salaries and employee benefits
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Before tax	26,745	[1]
Tax effect	(7,748)	[2]
Net of tax before allocation to noncontrolling interests	18,997
Net of tax attributable to noncontrolling interests	(24)	[2]
Net of tax attributable to MHFG shareholders	18,973
Accumulated Own Credit Risk Adjustment | Other Noninterest Income (Expenses)
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Before tax	(885)	[1]
Tax effect	271	[2]
Net of tax before allocation to noncontrolling interests	(614)
Net of tax attributable to noncontrolling interests	64	[2]
Net of tax attributable to MHFG shareholders	¥ (550)
[1]The financial statement line item in which the amounts in the before tax column are reported in the consolidated statements of income is listed to the right of the table.[2]The financial statement line items in which the amounts in the tax effect and the net of tax attributable to noncontrolling interest columns are reported in the consolidated statements of income are Income tax expense and Net income, respectively.

Regulatory Matters (Capital Req

Regulatory Matters (Capital Requirements and Regulatory Adjustments Over Transitional Period) (Detail)		12 Months Ended
		Mar. 31, 2022		Mar. 31, 2021	Mar. 31, 2019
Japan Gaap Schedule Of Compliance With Regulatory Capital Requirements Under Banking Regulations [Line Items]
Additional loss absorbency requirements for G-SIBs and D-SIBs		1%			1%
March 2021
Japan Gaap Schedule Of Compliance With Regulatory Capital Requirements Under Banking Regulations [Line Items]
Minimum total capital		8%
Phase out of recognition of capital instruments that no longer qualify as capital		10%
Capital conservation buffer		2.50%
Countercyclical capital buffer	[1]	0.01%
Additional loss absorbency requirements for G-SIBs and D-SIBs		1%	[2]	1%
Minimum Leverage Ratio		3%
March 2021 | Common Equity Tier 1 Capital
Japan Gaap Schedule Of Compliance With Regulatory Capital Requirements Under Banking Regulations [Line Items]
Minimum total capital		4.50%
March 2021 | Tier I
Japan Gaap Schedule Of Compliance With Regulatory Capital Requirements Under Banking Regulations [Line Items]
Minimum total capital		6%
March 2022
Japan Gaap Schedule Of Compliance With Regulatory Capital Requirements Under Banking Regulations [Line Items]
Minimum total capital		8%
Phase out of recognition of capital instruments that no longer qualify as capital		0%
Capital conservation buffer		2.50%
Countercyclical capital buffer	[1]	0.01%
Additional loss absorbency requirements for G-SIBs and D-SIBs	[2]	1%
Minimum Leverage Ratio		3%
March 2022 | Common Equity Tier 1 Capital
Japan Gaap Schedule Of Compliance With Regulatory Capital Requirements Under Banking Regulations [Line Items]
Minimum total capital		4.50%
March 2022 | Tier I
Japan Gaap Schedule Of Compliance With Regulatory Capital Requirements Under Banking Regulations [Line Items]
Minimum total capital		6%
March 2023
Japan Gaap Schedule Of Compliance With Regulatory Capital Requirements Under Banking Regulations [Line Items]
Minimum total capital		8%
Phase out of recognition of capital instruments that no longer qualify as capital
Capital conservation buffer		2.50%
Countercyclical capital buffer	[1]	0.01%
Additional loss absorbency requirements for G-SIBs and D-SIBs	[2]	1%
Minimum Leverage Ratio	[3]	3.50%
March 2023 | Common Equity Tier 1 Capital
Japan Gaap Schedule Of Compliance With Regulatory Capital Requirements Under Banking Regulations [Line Items]
Minimum total capital		4.50%
March 2023 | Tier I
Japan Gaap Schedule Of Compliance With Regulatory Capital Requirements Under Banking Regulations [Line Items]
Minimum total capital		6%
March 2024
Japan Gaap Schedule Of Compliance With Regulatory Capital Requirements Under Banking Regulations [Line Items]
Minimum total capital		8%
Phase out of recognition of capital instruments that no longer qualify as capital
Capital conservation buffer		2.50%
Countercyclical capital buffer	[1]	0.01%
Additional loss absorbency requirements for G-SIBs and D-SIBs	[2]	1%
Minimum Leverage Ratio		3.50%
March 2024 | Common Equity Tier 1 Capital
Japan Gaap Schedule Of Compliance With Regulatory Capital Requirements Under Banking Regulations [Line Items]
Minimum total capital		4.50%
March 2024 | Tier I
Japan Gaap Schedule Of Compliance With Regulatory Capital Requirements Under Banking Regulations [Line Items]
Minimum total capital		6%
[1]Figures assume that the countercyclical capital buffer will continue to be 0.01% after March 2023.[2]Figures assume that the additional loss absorbency requirements applied to the Group as a G-SIB and D-SIB continue to be 1.0% on a fully effective basis in future years.[3]This figure includes a leverage ratio buffer required to be met at 50% of the additional loss absorbency requirements applied to the Group as a G-SIB under the finalized Basel III reforms.

Regulatory Matters (Capital R_2

Regulatory Matters (Capital Requirements and Regulatory Adjustments Over Transitional Period) (Parenthetical) (Detail)		12 Months Ended
		Mar. 31, 2022	Mar. 31, 2019
Japan Gaap Schedule Of Compliance With Regulatory Capital Requirements Under Banking Regulations [Line Items]
Additional loss absorbency requirements for G-SIBs and D-SIBs		1%	1%
March 2022
Japan Gaap Schedule Of Compliance With Regulatory Capital Requirements Under Banking Regulations [Line Items]
Countercyclical capital buffer	[1]	0.01%
Additional loss absorbency requirements for G-SIBs and D-SIBs	[2]	1%
March 2023
Japan Gaap Schedule Of Compliance With Regulatory Capital Requirements Under Banking Regulations [Line Items]
Countercyclical capital buffer	[1]	0.01%
Additional loss absorbency requirements for G-SIBs and D-SIBs	[2]	1%
March 2023 | Basel III
Japan Gaap Schedule Of Compliance With Regulatory Capital Requirements Under Banking Regulations [Line Items]
Leverage ratio buffer		50%
March 2025
Japan Gaap Schedule Of Compliance With Regulatory Capital Requirements Under Banking Regulations [Line Items]
Additional loss absorbency requirements for G-SIBs and D-SIBs		1%
[1]Figures assume that the countercyclical capital buffer will continue to be 0.01% after March 2023.[2]Figures assume that the additional loss absorbency requirements applied to the Group as a G-SIB and D-SIB continue to be 1.0% on a fully effective basis in future years.

Regulatory Matters (Capital Ade

Regulatory Matters (Capital Adequacy Ratios of MHFG, MHBK, and MHTB Calculated in Accordance with Japanese GAAP and Guidelines Established by Financial Services Agency) (Detail) - JPY (¥) ¥ in Millions		Mar. 31, 2022		Mar. 31, 2021		Mar. 31, 2019
Common Equity Tier 1 capital:
Actual		¥ 2,256,768
Required, ratio		120%
Required, amount	[1]	¥ 126,000		¥ 135,000
Actual	[1]	¥ 425,000		¥ 519,000
Leverage Ratio:
Required, ratio		3%	[1]	3%	[1]	3%
Actual	[1]	10.09%		11.51%
Mizuho Financial Group Inc | Consolidated
Common Equity Tier 1 capital:
Required, amount	[2]	¥ 5,184,000		¥ 5,405,000
Actual		8,067,000		7,850,000
Required, amount	[2]	6,155,000		6,418,000
Actual		¥ 9,713,000		¥ 9,702,000
Required, ratio	[2]	9.51%		9.51%
Actual		15%		14.37%
Required, amount	[2]	¥ 7,450,000		¥ 7,767,000
Actual		¥ 11,351,000		¥ 11,385,000
Required, ratio	[2]	11.51%		11.51%
Actual		17.53%		16.87%
Required, amount	[1]	¥ 6,389,000		¥ 6,016,000
Actual	[1]	¥ 9,713,000		¥ 9,702,000
Common Equity Tier 1 capital:
Required, ratio	[2]	8.01%		8.01%
Actual		12.46%		11.63%
Leverage Ratio:
Required, ratio	[1]	3%		3%
Actual	[1]	4.56%		4.83%
Mizuho Bank Limited | Consolidated
Common Equity Tier 1 capital:
Required, amount		¥ 2,683,000		¥ 2,823,000
Actual		6,968,000		6,972,000
Required, amount		3,578,000		3,764,000
Actual		¥ 8,604,000		¥ 8,819,000
Required, ratio		6%		6%
Actual		14.42%		14.05%
Required, amount		¥ 4,771,000		¥ 5,019,000
Actual		¥ 10,150,000		¥ 10,400,000
Required, ratio		8%		8%
Actual		17.02%		16.57%
Required, amount	[1]	¥ 5,971,000		¥ 5,660,000
Actual	[1]	¥ 8,604,000		¥ 8,819,000
Common Equity Tier 1 capital:
Required, ratio		4.50%		4.50%
Actual		11.68%		11.11%
Leverage Ratio:
Required, ratio	[1]	3%		3%
Actual	[1]	4.32%		4.67%
Mizuho Bank Limited | Non-consolidated
Common Equity Tier 1 capital:
Required, amount		¥ 2,528,000		¥ 2,648,000
Actual		6,293,000		6,561,000
Required, amount		3,370,000		3,531,000
Actual		¥ 7,919,000		¥ 8,406,000
Required, ratio		6%		6%
Actual		14.09%		14.28%
Required, amount		¥ 4,494,000		¥ 4,708,000
Actual		¥ 9,483,000		¥ 9,987,000
Required, ratio		8%		8%
Actual		16.88%		16.96%
Required, amount	[1]	¥ 5,570,000		¥ 5,343,000
Actual	[1]	¥ 7,919,000		¥ 8,406,000
Common Equity Tier 1 capital:
Required, ratio		4.50%		4.50%
Actual		11.20%		11.14%
Leverage Ratio:
Required, ratio	[1]	3%		3%
Actual	[1]	4.26%		4.72%
Mizuho Trust & Banking Company Limited | Consolidated
Common Equity Tier 1 capital:
Required, amount		¥ 79,000		¥ 82
Actual		442,000		527,000
Required, amount		105,000		109,000
Actual		¥ 442,000		¥ 527,000
Required, ratio		6%		6%
Actual		25.18%		28.94%
Required, amount		¥ 140,000		¥ 146,000
Actual		¥ 442,000		¥ 527,000
Required, ratio		8%		8%
Actual		25.18%		28.94%
Required, amount	[1]	¥ 130,000		¥ 138,000
Actual	[1]	¥ 442,000		¥ 527,000
Common Equity Tier 1 capital:
Required, ratio		4.50%		4.50%
Actual		25.18%		28.94%
Leverage Ratio:
Required, ratio	[1]	3%		3%
Actual	[1]	10.20%		11.41%
Mizuho Trust & Banking Company Limited | Non-consolidated
Common Equity Tier 1 capital:
Required, amount		¥ 78,000		¥ 82,000
Actual		425,000		519,000
Required, amount		104,000		109,000
Actual		¥ 425,000		¥ 519,000
Required, ratio		6%		6%
Actual		24.40%		28.63%
Required, amount		¥ 139,000		¥ 145,000
Actual		¥ 425,000		¥ 519,000
Required, ratio		8%		8%
Actual		24.40%		28.64%
Common Equity Tier 1 capital:
Required, ratio		4.50%		4.50%
Actual		24.40%		28.63%
[1]The required and actual amounts disclosed above at March 31, 2021 and March 31, 2022 exclude amounts of deposits to the Bank of Japan.[2]The required ratios disclosed above, at March 31, 2021 and 2022, include the capital conservation buffer of 2.5%, the countercyclical capital buffer of 0.01% and the additional loss absorbency requirements for G-SIBs and D-SIBs of 1.0%, which are all in addition to the regulatory minima. The respective required amounts are determined by applying the ratios to the sum of the risk weighted assets and certain other risk amounts.

Regulatory Matters (Capital A_2

Regulatory Matters (Capital Adequacy Ratios of MHFG, MHBK, and MHTB Calculated in Accordance with Japanese GAAP and Guidelines Established by Financial Services Agency) (Parenthetical) (Detail)		12 Months Ended
		Mar. 31, 2022		Mar. 31, 2021	Mar. 31, 2019
Japan Gaap Schedule Of Compliance With Regulatory Capital Requirements Under Banking Regulations [Line Items]
Capital conservation buffer		2.50%		2.50%
Additional loss absorbency requirements for G-SIBs and D-SIBs		1%			1%
March 2020
Japan Gaap Schedule Of Compliance With Regulatory Capital Requirements Under Banking Regulations [Line Items]
Countercyclical capital buffer		0.01%		0.01%
March 2021
Japan Gaap Schedule Of Compliance With Regulatory Capital Requirements Under Banking Regulations [Line Items]
Additional loss absorbency requirements for G-SIBs and D-SIBs		1%	[1]	1%
Countercyclical capital buffer	[2]	0.01%
[1]Figures assume that the additional loss absorbency requirements applied to the Group as a G-SIB and D-SIB continue to be 1.0% on a fully effective basis in future years.[2]Figures assume that the countercyclical capital buffer will continue to be 0.01% after March 2023.

Regulatory Matters - Additional

Regulatory Matters - Additional Information (Detail) - JPY (¥) ¥ in Billions	12 Months Ended
	Mar. 31, 2022		Mar. 31, 2019	Mar. 31, 2021
Japan Gaap Schedule Of Compliance With Regulatory Capital Requirements [Line Items]
Capital adequacy ratio	120%
Increments of capital investment	10%
Tier 2 capital				¥ 168.7
Leverage ratio	3%	[1]	3%	3%	[1]
Additional loss absorbency requirements for G-SIBs and D-SIBs	1%		1%
Description of regulatory actions for not maintaining the minimum capital ratio concerning securities subsidiaries	A capital ratio of less than 140% will call for regulatory reporting and a capital ratio of less than 100% may lead to a temporary suspension of all or part of the business operations and further, to the cancellation of the license to act as a securities broker and dealer.
Maximum
Japan Gaap Schedule Of Compliance With Regulatory Capital Requirements [Line Items]
Buffer ranging percentage	2.50%
Minimum
Japan Gaap Schedule Of Compliance With Regulatory Capital Requirements [Line Items]
Buffer ranging percentage	0%
Minimum | Regulatory reporting
Japan Gaap Schedule Of Compliance With Regulatory Capital Requirements [Line Items]
Capital adequacy ratio	140%
Minimum | Temporary suspension
Japan Gaap Schedule Of Compliance With Regulatory Capital Requirements [Line Items]
Capital adequacy ratio	100%
Basel III
Japan Gaap Schedule Of Compliance With Regulatory Capital Requirements [Line Items]
Tier 1 capital ratio	6%
Common Equity Tier 1	4.50%
Basel III | Minimum
Japan Gaap Schedule Of Compliance With Regulatory Capital Requirements [Line Items]
Capital adequacy ratio	8%
[1]The required and actual amounts disclosed above at March 31, 2021 and March 31, 2022 exclude amounts of deposits to the Bank of Japan.

Earnings Per Common Share (Comp

Earnings Per Common Share (Computation of Basic and Diluted Earnings Per Common Share) (Detail) - JPY (¥) ¥ / shares in Units, shares in Thousands, ¥ in Millions		12 Months Ended
		Mar. 31, 2022	Mar. 31, 2021	Mar. 31, 2020
Net income (loss):
Net income (loss) attributable to MHFG common shareholders		¥ (104,722)	¥ 581,765	¥ 150,195
Effect of dilutive securities
Effect of dilutive securities
Net income (loss) attributable to common shareholders after assumed conversions		¥ (104,722)	¥ 581,765	¥ 150,195
Shares:
Weighted average common shares outstanding		2,537,051	2,537,513	2,537,368
Effect of dilutive securities:
Stock options and the common shares of MHFG under the stock compensation programs	[1]		89	158
Weighted average common shares after assumed conversions		2,537,051	2,537,602	2,537,526
Earnings per common share:
Basic net income (loss) per common share		¥ (41.28)	¥ 229.27	¥ 59.19
Diluted net income (loss) per common share	[1]	¥ (41.28)	¥ 229.26	¥ 59.19
[1]For the fiscal years ended March 31, 2020, 2021 and 2022, the performance-based plan under the stock compensation programs could potentially dilute earnings per common share but were not included in the computation of diluted earnings per common share due to their antidilutive effects. In addition, for the fiscal year ended March 31, 2022, the computation of diluted earnings per common share did not assume exercise of stock options, as the effect of such exercise would be anti-dilutive due to net loss.

Income Taxes (Components of Inc

Income Taxes (Components of Income Tax Expense (Benefit)) (Detail) - JPY (¥) ¥ in Millions	12 Months Ended
	Mar. 31, 2022	Mar. 31, 2021	Mar. 31, 2020
Current:
Domestic	¥ 42,401	¥ 81,023	¥ 96,231
Foreign	71,947	78,992	52,885
Total current tax expense	114,348	160,015	149,116
Deferred:
Domestic	(256,093)	55,927	(111,341)
Foreign	728	(5,226)	9,400
Total deferred tax expense (benefit)	(255,365)	50,701	(101,941)
Total income tax expense (benefit)	¥ (141,017)	¥ 210,716	¥ 47,175

Income Taxes (Detailed Amounts

Income Taxes (Detailed Amounts of Tax Effects of Items Recorded Directly in Equity) (Detail) - JPY (¥) ¥ in Millions	12 Months Ended
	Mar. 31, 2022	Mar. 31, 2021	Mar. 31, 2020
Net unrealized gains (losses) on available-for-sale securities:
Unrealized gains (losses)	¥ (16,489)	¥ (2,810)	¥ (10,012)
Less: reclassification adjustments	8,504	7,195	(8,410)
Total	(7,985)	4,385	(18,422)
Defined benefit plan adjustments:
Unrealized gains (losses)	(9,020)	143,653	(52,888)
Less: reclassification adjustments	(7,748)	(1,424)	(1,765)
Total	(16,768)	142,229	(54,653)
Own credit risk adjustments:
Unrealized gains (losses)	1,745	919	5,052
Less: reclassification adjustments	271	(1,911)	387
Total	2,016	(992)	5,439
Total tax effect before allocation to noncontrolling interests	¥ (22,737)	¥ 145,622	¥ (67,636)

Income Taxes - Additional Infor

Income Taxes - Additional Information (Detail) - JPY (¥) ¥ in Millions	12 Months Ended
	Mar. 31, 2022	Mar. 31, 2021	Mar. 31, 2020
Income Taxes [Line Items]
Net operating loss carryforwards	¥ 589,000
Changes that directly affected Income tax expense	16,196	¥ (39,410)	¥ 5,984
Change in valuation allowance	17,818	3,282	713
Unrecognized tax benefits, that would affect effective tax rate	5,245	4,401	3,374
Unrecognized tax benefits, interest and penalties	1,812	¥ 1,463	¥ 1,477
Mizuho Securities Company Limited | Japan
Income Taxes [Line Items]
Net operating loss carryforwards	246,000
Mizuho Financial Group Inc
Income Taxes [Line Items]
Undistributed earnings	285,000
Deferred tax liabilities	¥ 30,000

Income Taxes (Reconciliation of

Income Taxes (Reconciliation of Income Tax Expense at Effective Statutory Tax Rate to Actual Income Tax Expense) (Detail) - JPY (¥) ¥ in Millions		12 Months Ended
		Mar. 31, 2022		Mar. 31, 2021	Mar. 31, 2020
Reconciliation Of Income Tax Expense Benefit And Statutory Federal Tax Rate [Line Items]
Income (loss) before income tax expense (benefit)		¥ (242,488)		¥ 1,028,764	¥ 153,490
Effective statutory tax rate		30.62%		30.62%	30.62%
Income tax calculated at the statutory tax rate		¥ (74,250)		¥ 315,007	¥ 46,999
Income not subject to tax		(10,219)		(7,446)	(7,758)
Expenses not deductible for tax purposes		828		728	1,290
Tax rate differentials of subsidiaries		(8,035)		(9,252)	(5,756)
Change in valuation allowance		16,196	[1]	(39,410)	5,984
Noncontrolling interest income (loss) of consolidated VIEs		5,088		(70,143)	14,796
Effect of enacted change in tax rates		(29)		(213)	(210)
Reversal of outside basis differences	[1]	(122,633)
Foreign tax credit and payments		40,228		1,657	1,823
Income excluded from taxable income of enterprise tax		(6,944)		(5,076)	(4,040)
Other		18,753		24,864	(5,953)
Total income tax expense (benefit)		¥ (141,017)		¥ 210,716	¥ 47,175
[1]These amounts for the fiscal year ended March 31, 2022 represent mainly the reversal of an outside basis difference related to the share buyback conducted by MHSC in response to improving the capital position and aligning to the MHFG Group’s capital policy and the related increase in the valuation allowance.

Income Taxes (Components of Net

Income Taxes (Components of Net Deferred Tax Assets (Liabilities)) (Detail) - JPY (¥) ¥ in Millions		Mar. 31, 2022		Mar. 31, 2021		Mar. 31, 2020	Mar. 31, 2019
Deferred tax assets:
Allowance for credit losses		¥ 292,277		¥ 247,983
Lease liabilities		183,537		195,629
Trading securities		118,242		8,519
Premises and equipment		65,051		64,389
Derivative financial instruments		52,321		14,893
Available-for-sale securities		8,313		1,164
Net operating loss carryforwards	[2]	183,410	[1]	151,383
Other		223,564		237,730
Deferred Tax Assets, Gross, Total		1,126,715		921,690
Valuation allowance		(163,164)	[1],[2]	(129,150)	[2]	¥ (165,278)	¥ (158,581)
Deferred tax assets, net of valuation allowance		963,551		792,540
Deferred tax liabilities:
Prepaid pension cost and accrued pension liabilities		221,256		292,397
Right-of-use assets		176,591		188,902
Investments		213,398		259,276
Other		104,020		83,952
Deferred tax liabilities		715,265		824,527
Net deferred tax assets (liabilities)		¥ 248,286		¥ (31,987)
[1]The amount includes ¥0 million related to MHFG’s net operating loss carryforwards resulting mainly from intercompany capital transactions in relation to the share buyback conducted by MHSC as of March 31, 2022. The tax effect of the net operating loss carryforwards is substantially offset by ¥0 million of valuation allowance as a result of considering all available evidence regarding sources of future taxable income including historical trends in taxable income in the preceding periods and forecasted taxable income.[2]The amount includes ¥85,001 million and ¥0 million related to MHSC’s net operating loss carryforwards resulting mainly from the organizational restructuring of certain foreign subsidiaries as of March 31, 2021 and 2022, respectively. The tax effect of the net operating loss carryforwards is substantially offset by ¥56,928 million and ¥0 million, respectively, of valuation allowance as a result of considering all available evidence regarding sources of future taxable income including historical trends in taxable income in the preceding periods and forecasted taxable income.

Income Taxes (Components of N_2

Income Taxes (Components of Net Deferred Tax Assets (Liabilities)) (Parenthetical) (Detail) - JPY (¥) ¥ in Millions		Mar. 31, 2022		Mar. 31, 2021		Mar. 31, 2020	Mar. 31, 2019
Schedule Of Deferred Income Tax Assets And Liabilities [Line Items]
Net operating loss carryforwards	[2]	¥ 183,410	[1]	¥ 151,383
Valuation allowance		163,164	[1],[2]	129,150	[2]	¥ 165,278	¥ 158,581
Mizuho Securities Company Limited
Schedule Of Deferred Income Tax Assets And Liabilities [Line Items]
Net operating loss carryforwards		73,736		85,001
Valuation allowance		46,734		¥ 56,928
Mizuho Financial Group, Inc. [Member]
Schedule Of Deferred Income Tax Assets And Liabilities [Line Items]
Net operating loss carryforwards		26,633
Valuation allowance		¥ 24,675
[1]The amount includes ¥0 million related to MHFG’s net operating loss carryforwards resulting mainly from intercompany capital transactions in relation to the share buyback conducted by MHSC as of March 31, 2022. The tax effect of the net operating loss carryforwards is substantially offset by ¥0 million of valuation allowance as a result of considering all available evidence regarding sources of future taxable income including historical trends in taxable income in the preceding periods and forecasted taxable income.[2]The amount includes ¥85,001 million and ¥0 million related to MHSC’s net operating loss carryforwards resulting mainly from the organizational restructuring of certain foreign subsidiaries as of March 31, 2021 and 2022, respectively. The tax effect of the net operating loss carryforwards is substantially offset by ¥56,928 million and ¥0 million, respectively, of valuation allowance as a result of considering all available evidence regarding sources of future taxable income including historical trends in taxable income in the preceding periods and forecasted taxable income.

Income Taxes (Breakdown of Net

Income Taxes (Breakdown of Net Operating Loss Carryforwards by Tax Jurisdiction) (Detail) - JPY (¥) ¥ in Millions		Mar. 31, 2022		Mar. 31, 2021
Operating Loss Carryforwards [Line Items]
Deferred tax assets, operating loss carryforwards	[2]	¥ 183,410	[1]	¥ 151,383
Operating loss, Valuation allowance		(152,000)		(118,000)
Deferred tax assets, net of valuation allowance		31,000		33,000
Japan
Operating Loss Carryforwards [Line Items]
Deferred tax assets, operating loss carryforwards		106,000	[3]	94,000	[4]
Operating loss, Valuation allowance		(77,000)	[3]	(64,000)	[4]
Deferred tax assets, net of valuation allowance		29,000	[3]	30,000	[4]
United States of America
Operating Loss Carryforwards [Line Items]
Deferred tax assets, operating loss carryforwards		1,000		2,000
Deferred tax assets, net of valuation allowance		1,000		2,000
United Kingdom
Operating Loss Carryforwards [Line Items]
Deferred tax assets, operating loss carryforwards	[5]	75,000		54,000
Operating loss, Valuation allowance	[5]	(75,000)		(54,000)
Others
Operating Loss Carryforwards [Line Items]
Deferred tax assets, operating loss carryforwards		1,000		1,000
Deferred tax assets, net of valuation allowance		¥ 1,000		¥ 1,000
[1]The amount includes ¥0 million related to MHFG’s net operating loss carryforwards resulting mainly from intercompany capital transactions in relation to the share buyback conducted by MHSC as of March 31, 2022. The tax effect of the net operating loss carryforwards is substantially offset by ¥0 million of valuation allowance as a result of considering all available evidence regarding sources of future taxable income including historical trends in taxable income in the preceding periods and forecasted taxable income.[2]The amount includes ¥85,001 million and ¥0 million related to MHSC’s net operating loss carryforwards resulting mainly from the organizational restructuring of certain foreign subsidiaries as of March 31, 2021 and 2022, respectively. The tax effect of the net operating loss carryforwards is substantially offset by ¥56,928 million and ¥0 million, respectively, of valuation allowance as a result of considering all available evidence regarding sources of future taxable income including historical trends in taxable income in the preceding periods and forecasted taxable income.[3]¥74 billion of the Japan deferred tax assets of ¥106 billion is related to MHSC, which is substantially offset by a valuation allowance, and will expire during the fiscal year ending March 31, 2026. ¥27 billion of the Japan deferred tax assets of ¥106 billion is related to MHFG, which is substantially offset by a valuation allowance, and will mostly expire during the fiscal year ending March 31, 2032.[4]¥85 billion of the Japan deferred tax assets of ¥94 billion is related to MHSC, which is substantially offset by a valuation allowance, and will expire during the fiscal year ending March 31, 2026.[5]The United Kingdom net operating loss carryforwards may be carried forward indefinitely for tax purposes.

Income Taxes (Breakdown of Ne_2

Income Taxes (Breakdown of Net Operating Loss Carryforwards by Tax Jurisdiction) (Parenthetical) (Detail) - JPY (¥) ¥ in Millions		12 Months Ended
		Mar. 31, 2022		Mar. 31, 2021
Operating Loss Carryforwards [Line Items]
Deferred tax assets, operating loss carryforwards	[2]	¥ 183,410	[1]	¥ 151,383
Japan
Operating Loss Carryforwards [Line Items]
Deferred tax assets, operating loss carryforwards		106,000	[3]	94,000	[4]
Mizuho Securities Company Limited
Operating Loss Carryforwards [Line Items]
Deferred tax assets, operating loss carryforwards		73,736		85,001
Mizuho Securities Company Limited | Japan
Operating Loss Carryforwards [Line Items]
Deferred tax assets, operating loss carryforwards		¥ 74,000		¥ 85,000
Operating loss carryforwards, expiration date		Mar. 31, 2026		Mar. 31, 2026
Mizuho Financial Group, Inc. [Member]
Operating Loss Carryforwards [Line Items]
Deferred tax assets, operating loss carryforwards		¥ 26,633
Mizuho Financial Group, Inc. [Member] | Japan
Operating Loss Carryforwards [Line Items]
Deferred tax assets, operating loss carryforwards		¥ 27,000
Operating loss carryforwards, expiration date		Mar. 31, 2032
[1]The amount includes ¥0 million related to MHFG’s net operating loss carryforwards resulting mainly from intercompany capital transactions in relation to the share buyback conducted by MHSC as of March 31, 2022. The tax effect of the net operating loss carryforwards is substantially offset by ¥0 million of valuation allowance as a result of considering all available evidence regarding sources of future taxable income including historical trends in taxable income in the preceding periods and forecasted taxable income.[2]The amount includes ¥85,001 million and ¥0 million related to MHSC’s net operating loss carryforwards resulting mainly from the organizational restructuring of certain foreign subsidiaries as of March 31, 2021 and 2022, respectively. The tax effect of the net operating loss carryforwards is substantially offset by ¥56,928 million and ¥0 million, respectively, of valuation allowance as a result of considering all available evidence regarding sources of future taxable income including historical trends in taxable income in the preceding periods and forecasted taxable income.[3]¥74 billion of the Japan deferred tax assets of ¥106 billion is related to MHSC, which is substantially offset by a valuation allowance, and will expire during the fiscal year ending March 31, 2026. ¥27 billion of the Japan deferred tax assets of ¥106 billion is related to MHFG, which is substantially offset by a valuation allowance, and will mostly expire during the fiscal year ending March 31, 2032.[4]¥85 billion of the Japan deferred tax assets of ¥94 billion is related to MHSC, which is substantially offset by a valuation allowance, and will expire during the fiscal year ending March 31, 2026.

Income Taxes (Roll-forward of V

Income Taxes (Roll-forward of Valuation Allowance) (Detail) - JPY (¥) ¥ in Millions	12 Months Ended
	Mar. 31, 2022		Mar. 31, 2021		Mar. 31, 2020
Valuation Allowance [Line Items]
Balance at beginning of fiscal year	¥ 129,150	[1]	¥ 165,278		¥ 158,581
Changes that directly affected Income tax expense	16,196	[2]	(39,410)		5,984
Others	17,818		3,282		713
Total	17,818		3,282		713
Balance at end of fiscal year	¥ 163,164	[1],[3]	¥ 129,150	[1]	¥ 165,278
[1]The amount includes ¥85,001 million and ¥0 million related to MHSC’s net operating loss carryforwards resulting mainly from the organizational restructuring of certain foreign subsidiaries as of March 31, 2021 and 2022, respectively. The tax effect of the net operating loss carryforwards is substantially offset by ¥56,928 million and ¥0 million, respectively, of valuation allowance as a result of considering all available evidence regarding sources of future taxable income including historical trends in taxable income in the preceding periods and forecasted taxable income.[2]These amounts for the fiscal year ended March 31, 2022 represent mainly the reversal of an outside basis difference related to the share buyback conducted by MHSC in response to improving the capital position and aligning to the MHFG Group’s capital policy and the related increase in the valuation allowance.[3]The amount includes ¥0 million related to MHFG’s net operating loss carryforwards resulting mainly from intercompany capital transactions in relation to the share buyback conducted by MHSC as of March 31, 2022. The tax effect of the net operating loss carryforwards is substantially offset by ¥0 million of valuation allowance as a result of considering all available evidence regarding sources of future taxable income including historical trends in taxable income in the preceding periods and forecasted taxable income.

Income Taxes (Net Operating Los

Income Taxes (Net Operating Losses Carryforwards by Expiration Date) (Detail) ¥ in Billions	Mar. 31, 2022 JPY (¥)
Operating Loss Carryforwards [Line Items]
Net operating loss carryforwards	¥ 589
2023
Operating Loss Carryforwards [Line Items]
Net operating loss carryforwards	0
2024
Operating Loss Carryforwards [Line Items]
Net operating loss carryforwards	0
2025
Operating Loss Carryforwards [Line Items]
Net operating loss carryforwards	0
2026
Operating Loss Carryforwards [Line Items]
Net operating loss carryforwards	246
2027
Operating Loss Carryforwards [Line Items]
Net operating loss carryforwards	3
2028 and thereafter
Operating Loss Carryforwards [Line Items]
Net operating loss carryforwards	¥ 340	[1]
[1]Including the net operating loss carryforwards which may be carried forward indefinitely in the United Kingdom.

Income Taxes (Net Operating L_2

Income Taxes (Net Operating Losses Carryforwards by Expiration Date) (Parenthetical) (Detail) ¥ in Billions	12 Months Ended
	Mar. 31, 2022 JPY (¥)
Operating Loss Carryforwards [Line Items]
Net operating loss carryforwards	¥ 589
Mizuho Financial Group, Inc. [Member] | National Tax Agency, Japan [Member]
Operating Loss Carryforwards [Line Items]
Net operating loss carryforwards	499
Net operating loss carryforwards tax effected	¥ 24
Operating loss carryforwards, expiration date	Mar. 31, 2032

Income Taxes (Roll-forward of U

Income Taxes (Roll-forward of Unrecognized Tax Benefits) (Detail) - JPY (¥) ¥ in Millions	12 Months Ended
	Mar. 31, 2022	Mar. 31, 2021	Mar. 31, 2020
Operating Loss Carryforwards [Line Items]
Total unrecognized tax benefits at beginning of fiscal year	¥ 4,401	¥ 3,374	¥ 12,323
Gross amount of increases (decreases) related to positions taken during prior years	(576)	455	199
Gross amount of increases related to positions taken during the current year	954	524	328
Amount of decreases related to settlements			(9,420)
Foreign exchange translation	466	48	(56)
Total unrecognized tax benefits at end of fiscal year	¥ 5,245	¥ 4,401	¥ 3,374

Pension and Other Employee Be_3

Pension and Other Employee Benefit Plans (Components of Net Periodic Costs of Severance Indemnities and Pension Plans) (Detail) - JPY (¥) ¥ in Millions	12 Months Ended
	Mar. 31, 2022	Mar. 31, 2021	Mar. 31, 2020
Defined Benefit Plan Disclosure [Line Items]
Service cost-benefits earned during the fiscal year	¥ 33,190	¥ 39,672	¥ 45,697
Interest costs on projected benefit obligations	5,636	5,790	5,590
Expected return on plan assets	(37,051)	(41,887)	(40,551)
Amortization of prior service cost (benefits)	(4,820)	(2,378)	121
Amortization of net actuarial loss (gain)	(20,485)	1,671	(5,873)
Special termination benefits	10,791	9,569	9,793
Loss (gain) on settlement	0	(3,945)
Net periodic benefit cost	¥ (12,739)	¥ 8,492	¥ 14,777

Pension and Other Employee Be_4

Pension and Other Employee Benefit Plans - Additional Information (Detail) - JPY (¥) ¥ in Millions	12 Months Ended
	Mar. 31, 2022	Mar. 31, 2021	Mar. 31, 2020
Defined Benefit Plan Disclosure [Line Items]
Defined contribution plans, costs recognized in respect of contributions to the plans	¥ 3,981	¥ 4,510	¥ 3,142
Aggregated accumulated benefit obligations	¥ 1,377,739	¥ 1,437,843
Description of requirements for lump-sum severance indemnities	Employees with service in excess of one year are qualified to receive lump-sum severance indemnities.
Pension plan, contribution expected to be paid during the next fiscal year	¥ 29,000

Pension and Other Employee Be_5

Pension and Other Employee Benefit Plans (Other Changes in Plan Assets and Benefit Obligations Recognized in Other Comprehensive Income (Loss) Before-Tax) (Detail) - JPY (¥) ¥ in Millions	12 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Defined Benefit Plan Disclosure [Line Items]
Net actuarial gain (loss)	¥ (36,796)	¥ 395,028
Amortization of net actuarial loss (gain)	(20,485)	1,671
Settlement loss (gain) of net actuarial loss (gain)		(3,945)
Prior service benefits (cost)	(1)	74,160
Amortization of prior service cost (benefits)	(4,820)	(2,378)
Total recognized in other comprehensive income (loss) before-tax	¥ (62,102)	¥ 464,536

Pension and Other Employee Be_6

Pension and Other Employee Benefit Plans (Weighted-Average Assumptions Used to Determine Benefit Obligations and Net Periodic Benefit Cost) (Detail)	12 Months Ended
	Mar. 31, 2022	Mar. 31, 2021	Mar. 31, 2020
Weighted-average assumptions used to determine benefit obligations at fiscal year end:
Discount rates	0.52%	0.38%	0.37%
Rates of increase in future compensation levels	2%	1.80%
Interest credit rates	4.39%	4.38%	4.95%
Weighted-average assumptions used to determine net periodic benefit cost during the year:
Discount rates	0.38%	0.37%	0.34%
Rates of increase in future compensation levels	1.80%
Expected rates of return on plan assets	1.54%	1.79%	1.68%
Interest credit rates	4.38%	4.95%	4.97%
Minimum
Weighted-average assumptions used to determine benefit obligations at fiscal year end:
Rates of increase in future compensation levels			1.80%
Weighted-average assumptions used to determine net periodic benefit cost during the year:
Rates of increase in future compensation levels		1.80%	1.80%
Maximum
Weighted-average assumptions used to determine benefit obligations at fiscal year end:
Rates of increase in future compensation levels			4.80%
Weighted-average assumptions used to determine net periodic benefit cost during the year:
Rates of increase in future compensation levels		4.80%	4.80%

Pension and Other Employee Be_7

Pension and Other Employee Benefit Plans (Combined Funded Status and Amounts Recognized in Accompanying Consolidated Balance Sheets) (Detail) - JPY (¥) ¥ in Millions		12 Months Ended
		Mar. 31, 2022	Mar. 31, 2021	Mar. 31, 2020
Change in benefit obligations:
Benefit obligations at beginning of fiscal year		¥ 1,437,843	¥ 1,571,296
Service cost		33,190	39,672	¥ 45,697
Interest cost		5,636	5,790	5,590
Plan participants' contributions		1,089	1,131
Amendments	[1]	1	(74,160)
Actuarial loss (gain)		(19,939)	(6,938)
Foreign exchange translation		4,099	2,971
Benefits paid		(54,483)	(52,930)
Lump-sum payments		(29,697)	(27,357)
Settlement	[2]		(21,632)
Benefit obligations at end of fiscal year		1,377,739	1,437,843	1,571,296
Change in plan assets:
Fair value of plan assets at beginning of fiscal year		2,412,745	2,252,624
Actual return (negative return) on plan assets		(8,008)	395,555
Foreign exchange translation		3,863	3,570
Partial withdrawal of assets from employee retirement benefits trusts (Note)	[3]	(270,172)	(188,299)
Employer contributions		28,977	24,939
Plan participants' contributions		1,089	1,131
Benefits paid		(54,483)	(52,930)
Settlement	[2]		(23,845)
Fair value of plan assets at end of fiscal year		2,114,011	2,412,745	¥ 2,252,624
Funded status		736,272	974,902
Amounts recognized in the consolidated balance sheets consist of:
Prepaid pension cost		762,147	999,962
Accrued pension liability		(25,875)	(25,060)
Net amount recognized		736,272	974,902
Amounts recognized in Accumulated other comprehensive income (loss) before-tax consist of:
Prior service benefits (cost)		63,030	67,856
Net actuarial gain (loss)		421,690	478,966
Net amount recognized		¥ 484,720	¥ 546,822
[1]The amount of ¥74,160 million for March 31, 2021 includes ¥73,998 million of prior service benefits recognized during the six months ended September 30, 2020 related to an amendment to the defined benefit pension plans at MHFG and certain domestic subsidiaries. In September 2020, based on various approvals, MHFG and certain domestic subsidiaries communicated to their employees the amendment to the defined benefit pension plans that was effective as of October 1, 2020. In accordance with ASC 715, “Compensation—Retirement Benefits” (“ASC 715”), any change in projected benefit obligations due to a plan amendment is required to be recognized as prior service benefits (cost) as of the amendment date.[2]The amount of ¥21,632 million and ¥23,845 million of settlement for March 31, 2021 resulted from partial transition from the defined benefit pension plans to the defined contribution pension plans, which occurred during the second half of the fiscal year ended March 31, 2021 at MHFG and certain domestic subsidiaries. This partial transition constitutes a settlement under ASC 715 and any gain or loss is required to be recognized in the consolidated results of operations once settlement criteria are met. The settlement criteria were met during the second half of the fiscal year ended March 31, 2021.[3]During the fiscal year ended March 31, 2021 and 2022, certain subsidiaries of MHFG partially withdrew assets from employee retirement benefit trusts, which were established for the payment of employees’ severance pay and retirement pensions. Overall, the trusts remain in overfunded status as of March 31, 2022. No gains or losses have been recognized as a result of this transaction.

Pension and Other Employee Be_8

Pension and Other Employee Benefit Plans (Combined Funded Status and Amounts Recognized in Accompanying Consolidated Balance Sheets) (Parenthetical) (Detail) - JPY (¥) ¥ in Millions	12 Months Ended
	Mar. 31, 2022	Mar. 31, 2021	Mar. 31, 2020	Sep. 30, 2020
Defined Benefit Plan Disclosure [Line Items]
Gain (loss) recognized	¥ 0	¥ 3,945
Defined benefit plans, prior service costs recognised		74,160		¥ 73,998
Settlement		¥ 23,845	¥ 21,632

Pension and Other Employee Be_9

Pension and Other Employee Benefit Plans (Plans with Projected Benefit Obligations in Excess of Plan Assets and Plans with Accumulated Benefit Obligations in Excess of Plan Assets) (Detail) - JPY (¥) ¥ in Millions		Mar. 31, 2022	Mar. 31, 2021
Plans with projected benefit obligations in excess of plan assets:
Projected benefit obligations	[1]	¥ 31,829	¥ 49,110
Fair value of plan assets		5,954	24,050
Plans with accumulated benefit obligations in excess of plan assets:
Accumulated benefit obligations		31,829	49,110
Fair value of plan assets		¥ 5,954	¥ 24,050
[1]The plans with projected benefit obligations in excess of plan assets include those with accumulated benefit obligations in excess of plan assets.

Pension and Other Employee B_10

Pension and Other Employee Benefit Plans (Target Allocation for Plan Assets Excluding those of Employee Retirement Benefit Trusts) (Detail)	Mar. 31, 2022
Asset category
Plan assets	100%
General Account Assets
Asset category
Plan assets	11%	[1]
Other assets
Asset category
Plan assets	2%
Foreign | Equity securities
Asset category
Plan assets	25%
Foreign | Debt securities
Asset category
Plan assets	23%
Japan | Equity securities
Asset category
Plan assets	5%
Japan | Debt securities
Asset category
Plan assets	34%
[1]General account of life insurance companies is a contract with life insurance companies which guarantees payments of principal and predetermined interest payments.

Pension and Other Employee B_11

Pension and Other Employee Benefit Plans (Fair Value of Plan Assets by Asset Category) (Detail) - JPY (¥) ¥ in Millions		Mar. 31, 2022	Mar. 31, 2021		Mar. 31, 2020
Defined Benefit Plan Disclosure [Line Items]
Fair values of plan assets		¥ 2,114,011	¥ 2,412,745		¥ 2,252,624
Common stocks | Equity securities
Defined Benefit Plan Disclosure [Line Items]
Fair values of plan assets		1,003,000	1,291,000
Foreign | Common stocks | Equity securities
Defined Benefit Plan Disclosure [Line Items]
Fair values of plan assets		172,000	157,000
Foreign | Pooled funds | Equity securities
Defined Benefit Plan Disclosure [Line Items]
Fair values of plan assets	[1]	7,000	6,000
Foreign | Pooled funds | Debt securities
Defined Benefit Plan Disclosure [Line Items]
Fair values of plan assets	[1]	10,000	12,000
Foreign | Government bonds | Debt securities
Defined Benefit Plan Disclosure [Line Items]
Fair values of plan assets		179,000	187,000
Foreign | Other | Debt securities
Defined Benefit Plan Disclosure [Line Items]
Fair values of plan assets		18,000	19,000
All Other | General account of life insurance companies
Defined Benefit Plan Disclosure [Line Items]
Fair values of plan assets	[2]	116,000	115,000
All Other | Other Invested Assets
Defined Benefit Plan Disclosure [Line Items]
Fair values of plan assets		5,000	17,000
All Other | Net Asset Value
Defined Benefit Plan Disclosure [Line Items]
Fair values of plan assets	[3]	376,000	371,000
Japan | Common stocks | Equity securities
Defined Benefit Plan Disclosure [Line Items]
Fair values of plan assets	[4]	1,003,000	1,291,000
Japan | Pooled funds | Equity securities
Defined Benefit Plan Disclosure [Line Items]
Fair values of plan assets	[1]	18,000	18,000
Japan | Pooled funds | Debt securities
Defined Benefit Plan Disclosure [Line Items]
Fair values of plan assets	[1]	10,000	9,000
Japan | Government bonds | Debt securities
Defined Benefit Plan Disclosure [Line Items]
Fair values of plan assets		179,000	188,000
Japan | Other | Debt securities
Defined Benefit Plan Disclosure [Line Items]
Fair values of plan assets		21,000	23,000
Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair values of plan assets		1,567,000	1,859,000
Level 1 | Foreign | Common stocks | Equity securities
Defined Benefit Plan Disclosure [Line Items]
Fair values of plan assets		172,000	157,000
Level 1 | Foreign | Government bonds | Debt securities
Defined Benefit Plan Disclosure [Line Items]
Fair values of plan assets		170,000	180,000
Level 1 | All Other | Other Invested Assets
Defined Benefit Plan Disclosure [Line Items]
Fair values of plan assets		30,000	30,000	[5]
Level 1 | Japan | Common stocks | Equity securities
Defined Benefit Plan Disclosure [Line Items]
Fair values of plan assets	[4]	1,003,000	1,291,000
Level 1 | Japan | Pooled funds | Equity securities
Defined Benefit Plan Disclosure [Line Items]
Fair values of plan assets	[1]	13,000	13,000
Level 1 | Japan | Government bonds | Debt securities
Defined Benefit Plan Disclosure [Line Items]
Fair values of plan assets		179,000	188,000
Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair values of plan assets		171,000	183,000
Level 2 | Foreign | Pooled funds | Equity securities
Defined Benefit Plan Disclosure [Line Items]
Fair values of plan assets	[1]	7,000	6,000
Level 2 | Foreign | Pooled funds | Debt securities
Defined Benefit Plan Disclosure [Line Items]
Fair values of plan assets	[1]	10,000	12,000
Level 2 | Foreign | Government bonds | Debt securities
Defined Benefit Plan Disclosure [Line Items]
Fair values of plan assets		9,000	7,000
Level 2 | Foreign | Other | Debt securities
Defined Benefit Plan Disclosure [Line Items]
Fair values of plan assets		18,000	19,000
Level 2 | All Other | General account of life insurance companies
Defined Benefit Plan Disclosure [Line Items]
Fair values of plan assets	[2]	116,000	115,000
Level 2 | All Other | Other Invested Assets
Defined Benefit Plan Disclosure [Line Items]
Fair values of plan assets		(25,000)	(13,000)
Level 2 | Japan | Pooled funds | Equity securities
Defined Benefit Plan Disclosure [Line Items]
Fair values of plan assets	[1]	5,000	5,000
Level 2 | Japan | Pooled funds | Debt securities
Defined Benefit Plan Disclosure [Line Items]
Fair values of plan assets	[1]	10,000	9,000
Level 2 | Japan | Other | Debt securities
Defined Benefit Plan Disclosure [Line Items]
Fair values of plan assets		¥ 21,000	¥ 23,000
[1]These classes primarily include pension investment fund trusts. Investments in these classes are generally measured at fair value and can be redeemed within a short-term period upon request.[2]Investments in this class are measured at conversion value, which is equivalent to fair value.[3]In accordance with ASC 820, certain plan assets that are measured at fair value using the net asset value per share (or its equivalent) practical expedient have not been classified in the fair value hierarchy.[4]This class represents equity securities held in the employee retirement benefit trusts of ¥1,291 billion and ¥0 billion carried at fair value at March 31, 2021 and 2022, respectively, which are well-diversified across industries.[5]Amounts primarily include cash and short-term assets carried at fair value.

Pension and Other Employee B_12

Pension and Other Employee Benefit Plans (Fair Value of Plan Assets by Asset Category) (Parenthetical) (Detail) - JPY (¥) ¥ in Millions		Mar. 31, 2022	Mar. 31, 2021	Mar. 31, 2020
Defined Benefit Plan Disclosure [Line Items]
Equity securities held in the employee retirement benefit trusts		¥ 2,114,011	¥ 2,412,745	¥ 2,252,624
Equity securities | Common stocks
Defined Benefit Plan Disclosure [Line Items]
Equity securities held in the employee retirement benefit trusts		1,003,000	1,291,000
Equity securities | Common stocks | Japan
Defined Benefit Plan Disclosure [Line Items]
Equity securities held in the employee retirement benefit trusts	[1]	¥ 1,003,000	¥ 1,291,000
[1]This class represents equity securities held in the employee retirement benefit trusts of ¥1,291 billion and ¥0 billion carried at fair value at March 31, 2021 and 2022, respectively, which are well-diversified across industries.

Pension and Other Employee B_13

Pension and Other Employee Benefit Plans (Forecasted Benefit Payments Including Effect of Expected Future Service) (Detail) ¥ in Millions	Mar. 31, 2022 JPY (¥)
Defined Benefit Plan Disclosure [Line Items]
2023	¥ 76,933
2024	76,956
2025	76,662
2026	77,281
2027	75,557
2028-2032	¥ 344,156

Stock-based compensation - Addi

Stock-based compensation - Additional Information (Detail) ¥ / shares in Units, ¥ in Millions	12 Months Ended
	Mar. 31, 2022 JPY (¥) ¥ / shares shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation plan, exercise price per share	¥ 0
Cash deferred graded-vesting period	1 year
Compensation cost related to non-vested awards not yet recognized | ¥	¥ 1,485
Performance-based stock compensation, recognition period	1 year 10 months 17 days
MHFG Stock Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation plan, shares of common stock to be issued or transferred upon exercise of each of the stock acquisition rights | shares | shares	100
Stock-based compensation plan, exercise price per share	¥ 1
Stock-based compensation plan, contractual term (in years)	20 years

Stock-Based Compensation (Summa

Stock-Based Compensation (Summary of Stock-Based Compensation Plan) (Detail) ¥ / shares in Units, ¥ in Millions	12 Months Ended
	Mar. 31, 2022 JPY (¥) ¥ / shares shares
Number of shares
Outstanding at beginning of fiscal year | shares	85,700
Exercised during fiscal year | shares	24,200
Outstanding at end of fiscal year | shares	61,500
Weighted-average exercise price
Outstanding at beginning of fiscal year | ¥ / shares	¥ 1
Exercised during fiscal year | ¥ / shares	1
Outstanding at end of fiscal year | ¥ / shares	¥ 1
Weighted-average remaining contractual term
Outstanding at end of fiscal year	11 years 6 months 29 days
Aggregate intrinsic value
Outstanding at end of fiscal year | ¥	¥ 96

Stock-Based Compensation-Schedu

Stock-Based Compensation-Schedule Of Stock-Based Compensation Expense (Detail) - JPY (¥) ¥ in Millions	12 Months Ended
	Mar. 31, 2022	Mar. 31, 2021	Mar. 31, 2020
Stock Compensation Plan I
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
The compensation cost recognized	¥ 518	¥ 507	¥ 917
Stock Compensation Plan II
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
The compensation cost recognized	¥ 1,013	¥ 1,053	¥ 1,247

Stock-based Compensation - Stoc

Stock-based Compensation - Stock Option Activity (Detail) - JPY (¥) ¥ in Millions	12 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Stock Compensation Plan I
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Fair value of vested shares	¥ 518	¥ 507
Common stock shares acquired	518	507
Stock Compensation Plan II
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Fair value of vested shares	463	221
Common stock shares acquired	¥ 1,150	¥ 1,016

Stock-Based Compensation (Activ

Stock-Based Compensation (Activities Related to Performance-based Stock Compensation) (Detail) - Performance-based stock compensation - ¥ / shares	12 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Stock Compensation Plan I
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Nonvested at the beginning of the year	0	0
Number of shares, Granted during fiscal year	329,839	365,074
Number of shares, Vested during fiscal year	329,839	365,074
Number of shares, Forfeited during fiscal year	0	0
Nonvested at the end of the year	0	0
Weighted-average grant-date fair value, Nonvested at the beginning of the year	¥ 0	¥ 0
Weighted-average grant-date fair value, Granted during fiscal year	1,570.97	1,390.08
Weighted-average grant-date fair value, Vested during fiscal year	1,570.97	1,390.08
Weighted-average grant-date fair value, Forfeited during fiscal year	0	0
Weighted-average grant-date fair value, Nonvested at the ending of the year	¥ 0	¥ 0
Stock Compensation Plan II
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Nonvested at the beginning of the year	1,627,789	1,142,329
Number of shares, Granted during fiscal year	732,161	730,726
Number of shares, Vested during fiscal year	293,856	245,266
Number of shares, Forfeited during fiscal year	0	0
Nonvested at the end of the year	2,066,094	1,627,789
Weighted-average grant-date fair value, Nonvested at the beginning of the year	¥ 1,618.79	¥ 1,775.08
Weighted-average grant-date fair value, Granted during fiscal year	1,570.97	1,390.08
Weighted-average grant-date fair value, Vested during fiscal year	1,614.11	1,665.35
Weighted-average grant-date fair value, Forfeited during fiscal year	0	0
Weighted-average grant-date fair value, Nonvested at the ending of the year	¥ 1,602.51	¥ 1,618.79

Derivative Financial Instrume_3

Derivative Financial Instruments (Summary of Notional and Fair Value Amounts of Derivative Instruments Outstanding) (Detail) - JPY (¥) ¥ in Billions		Mar. 31, 2022	Mar. 31, 2021
Derivatives, Fair Value [Line Items]
Notional amount	[1]	¥ 1,635,837	¥ 1,376,353
Interest rate contracts
Derivatives, Fair Value [Line Items]
Notional amount	[1]	1,395,950	1,174,835
Foreign exchange contracts
Derivatives, Fair Value [Line Items]
Notional amount	[1]	217,462	182,809
Equity-related contracts
Derivatives, Fair Value [Line Items]
Notional amount	[1]	9,887	7,865
Credit-related contracts
Derivatives, Fair Value [Line Items]
Notional amount	[1]	11,857	10,431
Other contracts
Derivatives, Fair Value [Line Items]
Notional amount	[1]	681	413
Not Designated as Hedging Instrument
Derivatives, Fair Value [Line Items]
Fair value of derivative receivables	[2]	9,723	8,625
Fair value of derivative payables	[2]	9,770	8,252
Not Designated as Hedging Instrument | Interest rate contracts
Derivatives, Fair Value [Line Items]
Fair value of derivative receivables	[2]	4,624	4,639
Fair value of derivative payables	[2]	4,716	4,476
Not Designated as Hedging Instrument | Foreign exchange contracts
Derivatives, Fair Value [Line Items]
Fair value of derivative receivables	[2]	4,436	3,328
Fair value of derivative payables	[2]	4,472	3,246
Not Designated as Hedging Instrument | Equity-related contracts
Derivatives, Fair Value [Line Items]
Fair value of derivative receivables	[2]	426	531
Fair value of derivative payables	[2]	345	384
Not Designated as Hedging Instrument | Credit-related contracts
Derivatives, Fair Value [Line Items]
Fair value of derivative receivables	[2]	118	94
Fair value of derivative payables	[2]	121	113
Not Designated as Hedging Instrument | Other contracts
Derivatives, Fair Value [Line Items]
Fair value of derivative receivables	[2]	119	33
Fair value of derivative payables	[2]	¥ 116	¥ 33
[1]Notional amount includes the sum of gross long and gross short third-party contracts.[2]Derivative receivables and payables are recorded in Trading account assets and Trading account liabilities, respectively.

Derivative Financial Instrume_4

Derivative Financial Instruments - Additional Information (Detail) - JPY (¥) ¥ in Millions	Mar. 31, 2022	Mar. 31, 2021
Derivative [Line Items]
Cash collateral provided and not offset against derivative positions and included in Other assets	¥ 1,549,483	¥ 1,088,847
Cash collateral accepted and not offset against derivative positions and included in Other liabilities	1,075,591	763,642
Assets Needed for Immediate Settlement, Aggregate Fair Value	0	196,000
Mizuho Financial Group, Inc.
Derivative [Line Items]
Cash collateral provided and not offset against derivative positions and included in Other assets	¥ 1,549,000	¥ 1,108,000

Derivative Financial Instrume_5

Derivative Financial Instruments (Summary of Gains and Losses Information Related to Net Investment Hedges) (Detail) - JPY (¥) ¥ in Millions	12 Months Ended
	Mar. 31, 2022	Mar. 31, 2021	Mar. 31, 2020
Derivative Instruments, Gain (Loss) [Line Items]
Gains (losses) recorded in OCI	¥ (1,267)	¥ 1,483	¥ 418
Financial instruments hedging foreign exchange risk
Derivative Instruments, Gain (Loss) [Line Items]
Gains (losses) recorded in OCI	¥ (1,267)	¥ 1,483	¥ 418

Derivative Financial Instrume_6

Derivative Financial Instruments (Summary of Gains and Losses Information Related to Net Investment Hedges) (Parenthetical) (Detail) - JPY (¥) ¥ in Millions	12 Months Ended
	Mar. 31, 2022	Mar. 31, 2021	Mar. 31, 2020
Net Investment Hedging [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Accumulated other comprehensive income reclassified to earnings	¥ (1,336)	¥ 0	¥ (1,074)

Derivative Financial Instrume_7

Derivative Financial Instruments (Summary of Gains and Losses on Derivatives not Designated or Qualifying as Hedges) (Detail) - JPY (¥) ¥ in Millions		12 Months Ended
		Mar. 31, 2022	Mar. 31, 2021	Mar. 31, 2020
Derivative Instruments, Gain (Loss) [Line Items]
Gains (losses) recorded in income		¥ 737,778	¥ (157,122)	¥ 481,016
Interest rate contracts
Derivative Instruments, Gain (Loss) [Line Items]
Gains (losses) recorded in income		(130,312)	(27,893)	388,289
Foreign exchange contracts
Derivative Instruments, Gain (Loss) [Line Items]
Gains (losses) recorded in income		145,979	115,181	(111,920)
Equity-related contracts
Derivative Instruments, Gain (Loss) [Line Items]
Gains (losses) recorded in income	[1]	728,226	(209,488)	217,744
Credit-related contracts
Derivative Instruments, Gain (Loss) [Line Items]
Gains (losses) recorded in income	[2]	(13,877)	(58,602)	8,046
Other contracts
Derivative Instruments, Gain (Loss) [Line Items]
Gains (losses) recorded in income		¥ 7,762	¥ 23,680	¥ (21,143)
[1]The net gains (losses) excluded from the assessment of the effectiveness of fair value hedges is not included in the above table.[2]Amounts include the net gains (losses) of ¥2,838 million, ¥(2,956) million and ¥(605) million on the credit derivatives economically managing the credit risk of loans during the fiscal years ended March 31, 2020, 2021 and 2022, respectively.

Derivative Financial Instrume_8

Derivative Financial Instruments (Summary of Gains and Losses on Derivatives not Designated or Qualifying as Hedges) (Parenthetical) (Detail) - JPY (¥) ¥ in Millions		12 Months Ended
		Mar. 31, 2022	Mar. 31, 2021	Mar. 31, 2020
Derivative Instruments, Gain (Loss) [Line Items]
Gains (losses) recorded in income		¥ 737,778	¥ (157,122)	¥ 481,016
Credit-related contracts
Derivative Instruments, Gain (Loss) [Line Items]
Gains (losses) recorded in income	[1]	(13,877)	(58,602)	8,046
Credit-related contracts | Loans related to credit derivatives
Derivative Instruments, Gain (Loss) [Line Items]
Gains (losses) recorded in income		¥ (605)	¥ (2,956)	¥ 2,838
[1]Amounts include the net gains (losses) of ¥2,838 million, ¥(2,956) million and ¥(605) million on the credit derivatives economically managing the credit risk of loans during the fiscal years ended March 31, 2020, 2021 and 2022, respectively.

Derivative Financial Instrume_9

Derivative Financial Instruments (Summary of Notional and Fair Value Amounts of Credit Derivatives) (Detail) - JPY (¥) ¥ in Billions	Mar. 31, 2022	Mar. 31, 2021
Credit protection written
Credit Derivatives [Line Items]
Notional amount	¥ 5,167	¥ 4,559
Fair value	92	88
Credit protection written | Investment grade
Credit Derivatives [Line Items]
Notional amount	3,045	3,687
Fair value	38	71
Credit protection written | Non-investment grade
Credit Derivatives [Line Items]
Notional amount	2,122	872
Fair value	54	17
Credit protection purchased
Credit Derivatives [Line Items]
Notional amount	6,690	5,872
Fair value	¥ (95)	¥ (107)

Derivative Financial Instrum_10

Derivative Financial Instruments (Maximum Potential Amount of Future Payments for Credit Protection Written by Expiration Period) (Detail) - JPY (¥) ¥ in Billions	Mar. 31, 2022	Mar. 31, 2021
Credit Derivatives [Line Items]
Maximum payout/Notional amount	¥ 5,167	¥ 4,559
One year or less
Credit Derivatives [Line Items]
Maximum payout/Notional amount	245	249
After one year through five years
Credit Derivatives [Line Items]
Maximum payout/Notional amount	4,785	4,184
After five years
Credit Derivatives [Line Items]
Maximum payout/Notional amount	¥ 137	¥ 126

Derivative Financial Instrum_11

Derivative Financial Instruments (Quantitative Information about Derivative Instruments with Credit-risk-related Contingent Features) (Detail) - JPY (¥) ¥ in Millions	Mar. 31, 2022	Mar. 31, 2021
Credit Derivatives [Line Items]
Aggregate fair value of derivative instruments with credit-risk-related contingent features in net liability positions	¥ 1,149,000	¥ 780,000
Collateral provided to counterparties in the normal course of business	1,164,000	584,000
Amount required to be posted as collateral or settled immediately if credit-risk-related contingent features were triggered	¥ 0	¥ 196,000

Commitments and Contingencies -

Commitments and Contingencies - Additional Information (Detail) - JPY (¥) ¥ in Millions	12 Months Ended
	Mar. 31, 2022	Mar. 31, 2021	Mar. 31, 2020
Commitments And Contingencies Disclosure [Line Items]
Carrying amount of guarantees and similar obligations	¥ 443,000	¥ 160,000
Carrying amounts of derivatives that are deemed to guarantees	416,000	138,000
Allowance for credit losses on off-balance-sheet instruments	(14,819)	18,007	¥ 19,262
Other Liabilities
Commitments And Contingencies Disclosure [Line Items]
Allowance for credit losses on off-balance-sheet instruments	¥ 71,000	¥ 87,000

Commitments and Contingencies_2

Commitments and Contingencies (Summary of Maximum Potential Amount of Future Payments under Guarantees) (Detail) - JPY (¥) ¥ in Billions	Mar. 31, 2022	Mar. 31, 2021
Performance guarantees
Guarantor Obligations [Line Items]
Maximum potential/Contractual or Notional amount	¥ 3,254	¥ 2,730
Guarantees on loans
Guarantor Obligations [Line Items]
Maximum potential/Contractual or Notional amount	419	348
Guarantees on securities
Guarantor Obligations [Line Items]
Maximum potential/Contractual or Notional amount	75	79
Other guarantees
Guarantor Obligations [Line Items]
Maximum potential/Contractual or Notional amount	2,899	2,390
Guarantees for repayment of trust principal
Guarantor Obligations [Line Items]
Maximum potential/Contractual or Notional amount	22	28
Liabilities of trust accounts
Guarantor Obligations [Line Items]
Maximum potential/Contractual or Notional amount	478	480
Derivative financial instruments
Guarantor Obligations [Line Items]
Maximum potential/Contractual or Notional amount	36,484	23,933
One year or less | Performance guarantees
Guarantor Obligations [Line Items]
Maximum potential/Contractual or Notional amount	2,084	1,662
One year or less | Guarantees on loans
Guarantor Obligations [Line Items]
Maximum potential/Contractual or Notional amount	314	242
One year or less | Guarantees on securities
Guarantor Obligations [Line Items]
Maximum potential/Contractual or Notional amount	9	23
One year or less | Other guarantees
Guarantor Obligations [Line Items]
Maximum potential/Contractual or Notional amount	2,381	1,913
One year or less | Guarantees for repayment of trust principal
Guarantor Obligations [Line Items]
Maximum potential/Contractual or Notional amount	0	0
One year or less | Liabilities of trust accounts
Guarantor Obligations [Line Items]
Maximum potential/Contractual or Notional amount	116	61
One year or less | Derivative financial instruments
Guarantor Obligations [Line Items]
Maximum potential/Contractual or Notional amount	17,110	8,821
After one year through five years | Performance guarantees
Guarantor Obligations [Line Items]
Maximum potential/Contractual or Notional amount	996	882
After one year through five years | Guarantees on loans
Guarantor Obligations [Line Items]
Maximum potential/Contractual or Notional amount	42	84
After one year through five years | Guarantees on securities
Guarantor Obligations [Line Items]
Maximum potential/Contractual or Notional amount	66	56
After one year through five years | Other guarantees
Guarantor Obligations [Line Items]
Maximum potential/Contractual or Notional amount	451	348
After one year through five years | Guarantees for repayment of trust principal
Guarantor Obligations [Line Items]
Maximum potential/Contractual or Notional amount	9	13
After one year through five years | Liabilities of trust accounts
Guarantor Obligations [Line Items]
Maximum potential/Contractual or Notional amount	199	235
After one year through five years | Derivative financial instruments
Guarantor Obligations [Line Items]
Maximum potential/Contractual or Notional amount	15,721	12,048
After five years | Performance guarantees
Guarantor Obligations [Line Items]
Maximum potential/Contractual or Notional amount	174	186
After five years | Guarantees on loans
Guarantor Obligations [Line Items]
Maximum potential/Contractual or Notional amount	63	22
After five years | Guarantees on securities
Guarantor Obligations [Line Items]
Maximum potential/Contractual or Notional amount	0	0
After five years | Other guarantees
Guarantor Obligations [Line Items]
Maximum potential/Contractual or Notional amount	67	129
After five years | Guarantees for repayment of trust principal
Guarantor Obligations [Line Items]
Maximum potential/Contractual or Notional amount	13	15
After five years | Liabilities of trust accounts
Guarantor Obligations [Line Items]
Maximum potential/Contractual or Notional amount	163	184
After five years | Derivative financial instruments
Guarantor Obligations [Line Items]
Maximum potential/Contractual or Notional amount	¥ 3,653	¥ 3,064

Commitments and Contingencies_3

Commitments and Contingencies (Summary of Maximum Potential Amount of Future Payments of Certain Guarantees Classified Based on Internal Ratings) (Detail) - Performance guarantees, Guarantees on loans, Guarantees on securities and Other guarantees - JPY (¥) ¥ in Billions		Mar. 31, 2022	Mar. 31, 2021
Guarantor Obligations [Line Items]
Maximum potential/Contractual or Notional amount		¥ 6,647	¥ 5,547
Investment grade
Guarantor Obligations [Line Items]
Maximum potential/Contractual or Notional amount	[1]	5,336	4,427
Non-investment grade
Guarantor Obligations [Line Items]
Maximum potential/Contractual or Notional amount		¥ 1,311	¥ 1,120
[1]Investment grade in the internal rating scale generally corresponds to BBB- or above in the external rating scale.

Commitments and Contingencies_4

Commitments and Contingencies (Summary of Contractual Amounts with Regard to Undrawn Commitments) (Detail) - JPY (¥) ¥ in Billions		Mar. 31, 2022	Mar. 31, 2021
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Off-balance-sheet instruments, contractual amounts of the undrawn commitments		¥ 93,625	¥ 94,796
Commitments to Extend Credit
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Off-balance-sheet instruments, contractual amounts of the undrawn commitments	[1]	92,203	93,999
Commercial letters of credit
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Off-balance-sheet instruments, contractual amounts of the undrawn commitments		¥ 1,422	¥ 797
[1]Commitments to extend credit include commitments to invest in securities.

Commitments and contingencies_5

Commitments and contingencies - Schedule Of Balance Sheet Information Related to Operating Lease (Detail) - JPY (¥) ¥ in Millions		Mar. 31, 2022	Mar. 31, 2021
Commitments and Contingencies Disclosure [Abstract]
Right-of-use assets	[1]	¥ 570,171	¥ 611,533
Lease liabilities	[1]	¥ 593,339	¥ 636,541
Weighted average:
Remaining lease term		15 years 6 months	15 years 7 months 6 days
Discount rate		0.60%	0.54%
[1]Right-of-use assets and lease liabilities are included in Other assets and Other liabilities, respectively, on the consolidated balance sheets.

Commitments and contingencies_6

Commitments and contingencies - Schedule Of Operating Lease Cost And Supplemental Cash Flow Information (Detail) - JPY (¥) ¥ in Millions		12 Months Ended
		Mar. 31, 2022	Mar. 31, 2021	Mar. 31, 2020
Commitments and Contingencies Disclosure [Abstract]
Lease cost	[1]	¥ 111,907	¥ 119,453	¥ 126,840
Right-of-use assets obtained in exchange for new lease liabilities		51,901	108,430	60,047
Operating cash flows		¥ 101,223	¥ 102,150	¥ 102,066
[1]Lease cost for operating leases are included in Occupancy expenses on the consolidated statements of income. The Group’s variable lease costs and costs for leases with terms of twelve months or less are not significant.

Commitments and contingencies_7

Commitments and contingencies - Schedule Of Future Lease Payments Under Operating Leases (Detail) - JPY (¥) ¥ in Millions		Mar. 31, 2022	Mar. 31, 2021
Commitments and Contingencies Disclosure [Abstract]
2023		¥ 82,330
2024		60,138
2025		52,311
2026		41,991
2027		32,854
2028 and thereafter		347,734
Total lease payments		617,358
Amount representing interest		24,019
Total lease liabilities for operating leases	[1]	¥ 593,339	¥ 636,541
[1]Right-of-use assets and lease liabilities are included in Other assets and Other liabilities, respectively, on the consolidated balance sheets.

Variable Interest Entities an_3

Variable Interest Entities and Securitizations (Consolidated Assets of Consolidated VIEs as well as Total Assets and Maximum Exposure to Loss for Significant Unconsolidated VIEs) (Detail) - JPY (¥) ¥ in Millions	Mar. 31, 2022	Mar. 31, 2021	Mar. 31, 2020
Variable Interest Entity [Line Items]
Total assets of MHFG	¥ 231,550,704	¥ 221,651,474	¥ 211,218,800
Significant unconsolidated VIEs- Maximum exposure to loss	809,000	816,000
Consolidated VIEs
Variable Interest Entity [Line Items]
Total assets of MHFG	11,574,978	11,773,405
Unconsolidated VIEs
Variable Interest Entity [Line Items]
Total assets of MHFG	3,582,000	3,346,000
Asset-backed commercial paper/loan programs | Consolidated VIEs
Variable Interest Entity [Line Items]
Total assets of MHFG	2,709,000	2,628,000
Asset-backed securitizations
Variable Interest Entity [Line Items]
Significant unconsolidated VIEs- Maximum exposure to loss	90,000	48,000
Asset-backed securitizations | Consolidated VIEs
Variable Interest Entity [Line Items]
Total assets of MHFG	1,363,000	921,000
Asset-backed securitizations | Unconsolidated VIEs
Variable Interest Entity [Line Items]
Total assets of MHFG	190,000	127,000
Investments in securitization products | Consolidated VIEs
Variable Interest Entity [Line Items]
Total assets of MHFG	388,000	390,000
Investment funds
Variable Interest Entity [Line Items]
Significant unconsolidated VIEs- Maximum exposure to loss	719,000	768,000
Investment funds | Consolidated VIEs
Variable Interest Entity [Line Items]
Total assets of MHFG	1,816,000	2,299,000
Investment funds | Unconsolidated VIEs
Variable Interest Entity [Line Items]
Total assets of MHFG	3,392,000	3,219,000
Trust arrangements and other | Consolidated VIEs
Variable Interest Entity [Line Items]
Total assets of MHFG	¥ 5,299,000	¥ 5,535,000

Variable Interest Entities an_4

Variable Interest Entities and Securitizations (Carrying Amounts and Classification of Assets and Liabilities on Consolidated Balance Sheets that Relate to Variable Interests in Significant Unconsolidated VIEs) (Detail) - JPY (¥) ¥ in Millions		Mar. 31, 2022	Mar. 31, 2021	Mar. 31, 2020
Assets on consolidated balance sheets
Trading account assets		¥ 24,652,067	¥ 26,753,109
Loans		89,480,766	87,930,018
Total assets		231,550,704	221,651,474	¥ 211,218,800
Liabilities on MHFG's consolidated balance sheets and maximum exposure to loss related to unconsolidated VIEs
Payables under securities lending transactions		1,360,743	1,208,031
Trading account liabilities		14,859,383	10,877,538
Total		222,108,473	211,963,317
Maximum exposure to loss		809,000	816,000
Unconsolidated VIEs
Assets on consolidated balance sheets
Total assets		3,582,000	3,346,000
Mizuho Financial Group Inc | Unconsolidated VIEs
Assets on consolidated balance sheets
Trading account assets		143,000	127,000
Investments		430,000	513,000
Loans		92,000	66,000
Total assets		665,000	706,000
Liabilities on MHFG's consolidated balance sheets and maximum exposure to loss related to unconsolidated VIEs
Payables under securities lending transactions		54,000	53,000
Trading account liabilities		2,000	2,000
Total		56,000	55,000
Maximum exposure to loss	[1]	¥ 809,000	¥ 816,000
[1]This represents the maximum amount the Group could possibly be required to record in its consolidated statements of income associated with on-balance-sheet exposures and off-balance-sheet liabilities such as undrawn commitments.

Variable Interest Entities an_5

Variable Interest Entities and Securitizations - Additional Information (Detail) - JPY (¥) ¥ in Millions	Mar. 31, 2022	Mar. 31, 2021
Consolidated MHFG's balance sheets
Long-term debt	¥ 12,578,216	¥ 11,706,471
Noncontrolling interests	528,019	582,919
Unconsolidated VIEs
Consolidated MHFG's balance sheets
Noncontrolling interests	388,000	464,000
Debt Instrument [Member]
Consolidated MHFG's balance sheets
Long-term debt	367,000	332,000
Assets associated with securitization transactions
Consolidated MHFG's balance sheets
Transferred assets continue to be carried on the consolidated balance sheets	137,000	176,000
Assets associated with loan participation transactions
Consolidated MHFG's balance sheets
Transferred assets continue to be carried on the consolidated balance sheets	¥ 220,000	¥ 181,000

Summary of Noninterest Income (

Summary of Noninterest Income (Detail) - JPY (¥) ¥ in Millions		12 Months Ended
		Mar. 31, 2022	Mar. 31, 2021	Mar. 31, 2020
Disaggregation of Revenue [Line Items]
Fee and commission income		¥ 980,000	¥ 912,684	¥ 867,885
Foreign exchange gains (losses)—net	[1]	91,611	89,267	44,345
Trading account gains (losses)—net		(491,947)	120,596	745,692
Investment gains (losses)—net:
Debt securities		(14,777)	(22,032)	31,032
Equity securities		(60,563)	850,567	(557,391)
Equity in earnings (losses) of equity method investees—net	[2]	34,587	31,027	34,012
Gains on disposal of premises and equipment		9,943	7,125	2,583
Other noninterest income	[3],[4]	120,936	52,086	139,582
Total noninterest income		669,790	2,041,320	1,307,740
Premises and Equipment
Investment gains (losses)—net:
Gains on disposal of premises and equipment	[2]	9,943	7,125	2,583
Foreign Exchange
Disaggregation of Revenue [Line Items]
Foreign exchange gains (losses)—net	[2]	91,611	89,267	44,345
Trading Account Gains
Disaggregation of Revenue [Line Items]
Trading account gains (losses)—net	[3]	(491,947)	120,596	745,692
Debt securities
Investment gains (losses)—net:
Debt securities	[2]	(14,777)	(22,032)	31,032
Equity securities
Investment gains (losses)—net:
Equity securities	[2]	(60,563)	850,567	(557,391)
Securities related business
Disaggregation of Revenue [Line Items]
Fee and commission income	[5]	184,014	170,216	139,124
Deposits related business
Disaggregation of Revenue [Line Items]
Fee and commission income	[5]	15,358	15,162	14,668
Lending related business
Disaggregation of Revenue [Line Items]
Fee and commission income	[3],[6]	162,953	158,921	142,752
Correspondent clearing
Disaggregation of Revenue [Line Items]
Fee and commission income	[5]	103,979	109,111	112,275
Investment advisory, management and administrative service
Disaggregation of Revenue [Line Items]
Fee and commission income	[5]	122,014	104,753	98,720
Fiduciary and trust
Disaggregation of Revenue [Line Items]
Fee and commission income	[5]	141,365	122,215	129,298
Agency business
Disaggregation of Revenue [Line Items]
Fee and commission income	[5]	36,899	31,331	31,879
Guarantee-related business
Disaggregation of Revenue [Line Items]
Fee and commission income	[2]	35,296	31,665	28,974
Financial service, other
Disaggregation of Revenue [Line Items]
Fee and commission income	[5]	178,122	169,310	170,195
Financial service
Disaggregation of Revenue [Line Items]
Fee and commission income		¥ 980,000	¥ 912,684	¥ 867,885
[1]Amounts include realized and unrealized gains and losses on both derivative instruments and nonderivative instruments. Amounts on derivative instruments include gains and losses on forward foreign exchange contracts and currency options. Amounts on nonderivative instruments include translation gains and losses related to foreign currency-denominated debt securities reported as Trading securities.[2]These amounts are revenues from contracts that do not meet the scope of ASC 606.[3]Part of these amounts are considered to be revenues from contracts that are within the scope of ASC 606.[4]These amounts include the net unrealized gains resulting from changes in fair values of structured notes that contain embedded derivatives. See Note 27 “Fair value” for further details.[5]These amounts are revenues from contracts within the scope of ASC 606, “Revenue from contracts with customers” (“ASC 606”).[6]Most of the lending-related fees such as commitment fees and arrangement fees are not within the scope of ASC 606.

Noninterest Income - Additional

Noninterest Income - Additional Information (Detail) - JPY (¥) ¥ in Millions		12 Months Ended
		Mar. 31, 2022	Mar. 31, 2021	Mar. 31, 2020
Other Revenues [Line Items]
Trust fees		¥ 56,000	¥ 51,000	¥ 54,000
Fees related to trust business		85,000	71,000	75,000
Trading account gains (losses)—net		(491,947)	120,596	745,692
Other noninterest income	[1],[2]	120,936	52,086	139,582
Revenue from contracts with customers ("ASC 606")
Other Revenues [Line Items]
Trading account gains (losses)—net		83,000	86,000	60,000
Other noninterest income		¥ 15,000	¥ 15,000	¥ 24,000
[1]Part of these amounts are considered to be revenues from contracts that are within the scope of ASC 606.[2]These amounts include the net unrealized gains resulting from changes in fair values of structured notes that contain embedded derivatives. See Note 27 “Fair value” for further details.

Trading Account Gains and Los_3

Trading Account Gains and Losses (Net Trading Gains and Losses) (Detail) - JPY (¥) ¥ in Millions		12 Months Ended
		Mar. 31, 2022	Mar. 31, 2021	Mar. 31, 2020
Schedule of Trading Securities and Other Trading Assets [Line Items]
Trading account gains (losses)—net		¥ (491,947)	¥ 120,596	¥ 745,692
Foreign exchange gains (losses)—net	[1]	91,611	89,267	44,345
Net trading gains (losses)		(400,336)	209,863	790,037
Interest rate contracts
Schedule of Trading Securities and Other Trading Assets [Line Items]
Trading account gains (losses)—net		(130,312)	(27,893)	388,289
Foreign exchange contracts
Schedule of Trading Securities and Other Trading Assets [Line Items]
Trading account gains (losses)—net	[2]	145,979	115,181	(111,920)
Equity-related contracts
Schedule of Trading Securities and Other Trading Assets [Line Items]
Trading account gains (losses)—net		728,226	(209,488)	217,744
Credit-related contracts
Schedule of Trading Securities and Other Trading Assets [Line Items]
Trading account gains (losses)—net	[3]	(13,272)	(55,646)	5,208
Other contracts
Schedule of Trading Securities and Other Trading Assets [Line Items]
Trading account gains (losses)—net		7,762	23,680	(21,143)
Trading securities
Schedule of Trading Securities and Other Trading Assets [Line Items]
Trading account gains (losses)—net		¥ (1,230,330)	¥ 274,762	¥ 267,514
[1]Amounts include realized and unrealized gains and losses on both derivative instruments and nonderivative instruments. Amounts on derivative instruments include gains and losses on forward foreign exchange contracts and currency options. Amounts on nonderivative instruments include translation gains and losses related to foreign currency-denominated debt securities reported as Trading securities.[2]Amounts include gains and losses on currency swaps.[3]Amounts do not include the net gains (losses) of ¥2,838 million, ¥(2,956) million and ¥(605) million on the credit derivatives economically managing the credit risk of loans during the fiscal years ended March 31, 2020, 2021 and 2022, respectively. The net gains (losses) is recorded in Other noninterest income (expenses).

Trading Account Gains and Los_4

Trading Account Gains and Losses (Net Trading Gains and Losses) (Parenthetical) (Detail) - JPY (¥) ¥ in Millions		12 Months Ended
		Mar. 31, 2022	Mar. 31, 2021	Mar. 31, 2020
Schedule of Trading Securities and Other Trading Assets [Line Items]
Gains (losses) recorded in income		¥ 737,778	¥ (157,122)	¥ 481,016
Credit-related contracts
Schedule of Trading Securities and Other Trading Assets [Line Items]
Gains (losses) recorded in income	[1]	(13,877)	(58,602)	8,046
Credit-related contracts | Loans related to credit derivatives
Schedule of Trading Securities and Other Trading Assets [Line Items]
Gains (losses) recorded in income		¥ (605)	¥ (2,956)	¥ 2,838
[1]Amounts include the net gains (losses) of ¥2,838 million, ¥(2,956) million and ¥(605) million on the credit derivatives economically managing the credit risk of loans during the fiscal years ended March 31, 2020, 2021 and 2022, respectively.

Fair Value - Additional Informa

Fair Value - Additional Information (Detail) - JPY (¥) ¥ in Billions	12 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Fair value of assets transferred into Level 3		¥ 1
Carrying amounts of other equity interests of which fair value is not readily determinable	¥ 207	186
Senior borrowings and bonds
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
The differences between the aggregate fair value and aggregate unpaid principal balance of the notes for which the fair value option has been elected	90	14
Net unrealized gains (losses) resulting from changes in fair values of the notes	¥ 38	(10)
Investment funds
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Underlying assets, estimated remaining liquidation period	10 years
Long-term debt
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Fair value of assets transferred into Level 3	¥ 4
Fair value of liabilities transferred into Level 3	4	20
Fair value of liabilities transferred out of Level 3	6	42
Derived
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Fair value of liabilities transferred out of Level 3		1
Trading securities
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Fair value of assets transferred out of Level 3	452	1
Available-for-sale securities
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Fair value of assets transferred into Level 3		12
Fair value of assets transferred out of Level 3	693	22
Available-for-sale securities | Non Japanese Corporate Bonds [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Fair value of assets transferred into Level 3		¥ 12
Fair value of assets transferred out of Level 3	¥ 4

Fair Value (Summary of Assets a

Fair Value (Summary of Assets and Liabilities Measured at Fair Value on a Recurring Basis, Including Fair Value Option Elected) (Detail) - JPY (¥) ¥ in Millions		Mar. 31, 2022		Mar. 31, 2021
Assets:
Available-for-sale securities		¥ 31,673,890		¥ 27,853,035
Liabilities:
Long-term debt		2,756,062		2,703,021
Fair Value, Measurements, Recurring
Assets:
Equity securities with readily determinable fair values		3,155,000		3,479,000
Equity securities measured at net asset value	[1]	210,000		121,000
Securities measured at net asset value	[1],[2]	284,000		431,000
Other investments		58,000		55,000
Total assets measured at fair value		59,749,000		58,261,000
Liabilities:
Trading securities sold, not yet purchased		5,089,000		2,626,000
Long-term debt	[3]	2,756,000		2,703,000
Total liabilities measured at fair value		17,615,000		13,581,000
Fair Value, Measurements, Recurring | Interest rate contracts
Assets:
Assets, derivatives		4,624,000		4,639,000
Liabilities:
Liabilities, derivatives		4,716,000		4,476,000
Fair Value, Measurements, Recurring | Foreign exchange contracts
Assets:
Assets, derivatives		4,436,000		3,328,000
Liabilities:
Liabilities, derivatives		4,472,000		3,246,000
Fair Value, Measurements, Recurring | Equity-related contracts
Assets:
Assets, derivatives		426,000		531,000
Liabilities:
Liabilities, derivatives		345,000		384,000
Fair Value, Measurements, Recurring | Credit-related contracts
Assets:
Assets, derivatives		118,000		94,000
Liabilities:
Liabilities, derivatives		121,000		113,000
Fair Value, Measurements, Recurring | Other contracts
Assets:
Assets, derivatives		119,000		33,000
Liabilities:
Liabilities, derivatives		116,000		33,000
Fair Value, Measurements, Recurring | Japanese government bonds
Assets:
Assets, trading securities	[2]	1,615,000		1,934,000
Available-for-sale securities		25,159,000		20,921,000
Fair Value, Measurements, Recurring | Japanese local government bonds
Assets:
Assets, trading securities	[2]	145,000		120,000
Available-for-sale securities		420,000		463,000
Fair Value, Measurements, Recurring | U.S. Treasury bonds and federal agency securities
Assets:
Assets, trading securities	[2]	3,064,000		4,148,000
Available-for-sale securities		373,000		911,000
Fair Value, Measurements, Recurring | Other foreign government bonds
Assets:
Assets, trading securities	[2]	1,546,000		1,275,000
Available-for-sale securities		1,336,000		1,507,000
Fair Value, Measurements, Recurring | Agency mortgage-backed securities
Assets:
Assets, trading securities	[2]	3,176,000		4,727,000
Available-for-sale securities		451,000		521,000
Fair Value, Measurements, Recurring | Residential mortgage-backed securities
Assets:
Assets, trading securities	[2]	8,000		9,000
Available-for-sale securities		58,000		71,000
Fair Value, Measurements, Recurring | Commercial mortgage-backed securities
Assets:
Available-for-sale securities		854,000		716,000
Fair Value, Measurements, Recurring | Certificates of deposit and commercial paper
Assets:
Assets, trading securities	[2]	640,000		1,204,000
Fair Value, Measurements, Recurring | Corporate bonds and other debt securities
Assets:
Assets, trading securities	[2],[4]	2,829,000		2,705,000
Fair Value, Measurements, Recurring | Equity securities
Assets:
Assets, trading securities		1,622,000	[2]	1,575,000	[4]
Fair Value, Measurements, Recurring | Japanese corporate bonds and other debt securities
Assets:
Available-for-sale securities		2,235,000		1,904,000
Fair Value, Measurements, Recurring | Foreign corporate bonds and other debt securities
Assets:
Available-for-sale securities		788,000		839,000
Fair Value, Measurements, Recurring | Level 1
Assets:
Equity securities with readily determinable fair values		3,094,000		3,375,000
Other investments		2,000		2,000
Total assets measured at fair value		34,969,000		33,160,000
Liabilities:
Trading securities sold, not yet purchased		3,054,000		2,138,000
Total liabilities measured at fair value		3,284,000		2,433,000
Fair Value, Measurements, Recurring | Level 1 | Interest rate contracts
Assets:
Assets, derivatives		89,000		63,000
Liabilities:
Liabilities, derivatives		80,000		64,000
Fair Value, Measurements, Recurring | Level 1 | Equity-related contracts
Assets:
Assets, derivatives		77,000		170,000
Liabilities:
Liabilities, derivatives		122,000		224,000
Fair Value, Measurements, Recurring | Level 1 | Other contracts
Assets:
Assets, derivatives		49,000		10,000
Liabilities:
Liabilities, derivatives		28,000		7,000
Fair Value, Measurements, Recurring | Level 1 | Japanese government bonds
Assets:
Assets, trading securities	[2]	1,604,000		1,923,000
Available-for-sale securities		24,662,000		20,598,000
Fair Value, Measurements, Recurring | Level 1 | U.S. Treasury bonds and federal agency securities
Assets:
Assets, trading securities	[2]	2,353,000		3,544,000
Available-for-sale securities		373,000		911,000
Fair Value, Measurements, Recurring | Level 1 | Other foreign government bonds
Assets:
Assets, trading securities	[2]	907,000		775,000
Available-for-sale securities		363,000		535,000
Fair Value, Measurements, Recurring | Level 1 | Corporate bonds and other debt securities
Assets:
Assets, trading securities	[2],[4]	15,000		34,000
Fair Value, Measurements, Recurring | Level 1 | Equity securities
Assets:
Assets, trading securities		1,381,000	[2]	1,220,000	[4]
Fair Value, Measurements, Recurring | Level 2
Assets:
Equity securities with readily determinable fair values		61,000		104,000
Total assets measured at fair value		23,539,000		22,111,000
Liabilities:
Trading securities sold, not yet purchased		2,035,000		488,000
Long-term debt	[3]	1,962,000		1,990,000
Total liabilities measured at fair value		13,444,000		10,369,000
Fair Value, Measurements, Recurring | Level 2 | Interest rate contracts
Assets:
Assets, derivatives		4,513,000		4,564,000
Liabilities:
Liabilities, derivatives		4,636,000		4,408,000
Fair Value, Measurements, Recurring | Level 2 | Foreign exchange contracts
Assets:
Assets, derivatives		4,404,000		3,304,000
Liabilities:
Liabilities, derivatives		4,472,000		3,245,000
Fair Value, Measurements, Recurring | Level 2 | Equity-related contracts
Assets:
Assets, derivatives		323,000		339,000
Liabilities:
Liabilities, derivatives		183,000		117,000
Fair Value, Measurements, Recurring | Level 2 | Credit-related contracts
Assets:
Assets, derivatives		116,000		91,000
Liabilities:
Liabilities, derivatives		120,000		112,000
Fair Value, Measurements, Recurring | Level 2 | Other contracts
Assets:
Assets, derivatives		18,000		6,000
Liabilities:
Liabilities, derivatives		36,000		9,000
Fair Value, Measurements, Recurring | Level 2 | Japanese government bonds
Assets:
Assets, trading securities	[2]	11,000		11,000
Available-for-sale securities		497,000		323,000
Fair Value, Measurements, Recurring | Level 2 | Japanese local government bonds
Assets:
Assets, trading securities	[2]	145,000		120,000
Available-for-sale securities		420,000		463,000
Fair Value, Measurements, Recurring | Level 2 | U.S. Treasury bonds and federal agency securities
Assets:
Assets, trading securities	[2]	711,000		604,000
Fair Value, Measurements, Recurring | Level 2 | Other foreign government bonds
Assets:
Assets, trading securities	[2]	639,000		500,000
Available-for-sale securities		973,000		972,000
Fair Value, Measurements, Recurring | Level 2 | Agency mortgage-backed securities
Assets:
Assets, trading securities	[2]	3,176,000		4,727,000
Available-for-sale securities		451,000		521,000
Fair Value, Measurements, Recurring | Level 2 | Residential mortgage-backed securities
Assets:
Available-for-sale securities		40,000		48,000
Fair Value, Measurements, Recurring | Level 2 | Commercial mortgage-backed securities
Assets:
Available-for-sale securities		854,000
Fair Value, Measurements, Recurring | Level 2 | Certificates of deposit and commercial paper
Assets:
Assets, trading securities	[2]	640,000		1,204,000
Fair Value, Measurements, Recurring | Level 2 | Corporate bonds and other debt securities
Assets:
Assets, trading securities	[2],[4]	2,743,000		1,638,000
Fair Value, Measurements, Recurring | Level 2 | Equity securities
Assets:
Assets, trading securities		213,000	[2]	326,000	[4]
Fair Value, Measurements, Recurring | Level 2 | Japanese corporate bonds and other debt securities
Assets:
Available-for-sale securities		1,920,000		1,539,000
Fair Value, Measurements, Recurring | Level 2 | Foreign corporate bonds and other debt securities
Assets:
Available-for-sale securities		671,000		707,000
Fair Value, Measurements, Recurring | Level 3
Assets:
Other investments		56,000		53,000
Total assets measured at fair value		747,000		2,438,000
Liabilities:
Long-term debt	[3]	794,000		713,000
Total liabilities measured at fair value		887,000		779,000
Fair Value, Measurements, Recurring | Level 3 | Interest rate contracts
Assets:
Assets, derivatives		22,000		12,000
Liabilities:
Liabilities, derivatives				4,000
Fair Value, Measurements, Recurring | Level 3 | Foreign exchange contracts
Assets:
Assets, derivatives		32,000		24,000
Liabilities:
Liabilities, derivatives				1,000
Fair Value, Measurements, Recurring | Level 3 | Equity-related contracts
Assets:
Assets, derivatives		26,000		22,000
Liabilities:
Liabilities, derivatives		40,000		43,000
Fair Value, Measurements, Recurring | Level 3 | Credit-related contracts
Assets:
Assets, derivatives		2,000		3,000
Liabilities:
Liabilities, derivatives		1,000		1,000
Fair Value, Measurements, Recurring | Level 3 | Other contracts
Assets:
Assets, derivatives		52,000		17,000
Liabilities:
Liabilities, derivatives		52,000		17,000
Fair Value, Measurements, Recurring | Level 3 | Residential mortgage-backed securities
Assets:
Assets, trading securities	[2]	8,000		9,000
Available-for-sale securities		18,000		23,000
Fair Value, Measurements, Recurring | Level 3 | Commercial mortgage-backed securities
Assets:
Available-for-sale securities				716,000
Fair Value, Measurements, Recurring | Level 3 | Corporate bonds and other debt securities
Assets:
Assets, trading securities	[2],[4]	71,000		1,033,000
Fair Value, Measurements, Recurring | Level 3 | Equity securities
Assets:
Assets, trading securities		28,000	[2]	29,000	[4]
Fair Value, Measurements, Recurring | Level 3 | Japanese corporate bonds and other debt securities
Assets:
Available-for-sale securities		315,000		365,000
Fair Value, Measurements, Recurring | Level 3 | Foreign corporate bonds and other debt securities
Assets:
Available-for-sale securities		¥ 117,000		¥ 132,000
[1]In accordance with ASC 820, certain investments that are measured at fair value using the net asset value per share (or its equivalent) practical expedient have not been classified in the fair value hierarchy. The fair value amounts presented for these classes of assets are intended to permit the reconciliation of the fair value hierarchy to the amounts presented in the statements of financial position. The amounts of unfunded commitments related to these investments at March 31, 2021 and 2022 were ¥55 billion and ¥68 billion, respectively.[2]Trading securities include foreign currency denominated securities for which the MHFG Group elected the fair value option.[3]Amounts represent items for which the Group elected the fair value option or for which it applied the practicability exception.[4]The amount includes CLO and convertible bonds, which are classified in Level 3.

Fair Value (Summary of Assets_2

Fair Value (Summary of Assets and Liabilities Measured at Fair Value on a Recurring Basis, Including Fair Value Option Elected) (Parenthetical) (Detail) - JPY (¥) ¥ in Billions	Mar. 31, 2022	Mar. 31, 2021
Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Unfunded commitments	¥ 68	¥ 55

Fair Value (Reconciliation for

Fair Value (Reconciliation for All Assets and Liabilities Measured at Fair Value on a Recurring Basis Using Significant Unobservable Inputs (Level 3) (Detail) - JPY (¥) ¥ in Millions		12 Months Ended
		Mar. 31, 2022	Mar. 31, 2021
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Transfers into Level 3			¥ 1,000
Trading securities sold, not yet purchased
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Purchases			(1,000)
Sales			1,000
Long-term debt
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Transfers into Level 3		¥ 4,000
Beginning Balance		713,000	621,000
Gains (losses) in Earnings	[1]	61,000	(66,000)
Gains (losses) in OCI	[2]	1,000	(19,000)
Transfers into Level 3		4,000	20,000
Transfers out of level 3		(6,000)	(42,000)
Issuances		534	374,000
Settlements		(389,000)	(345,000)
Ending Balance		794,000	713,000
Change in unrealized gain (losses) still held	[3]	77,000	(34,000)
Trading securities
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Transfers out of level 3		(452,000)	(1,000)
Trading securities | Residential mortgage-backed securities
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning Balance		9,000	10,000
Settlements		(1,000)	(1,000)
Ending Balance		8,000	9,000
Trading securities | Corporate bonds and other debt securities
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning Balance		1,033,000	1,115,000
Gains (losses) in Earnings	[4]	7,000	70,000
Transfers out of level 3		(452,000)	(1,000)
Purchases		143,000	443,000
Sales		(72,000)	(216,000)
Issuances		0
Settlements		(588,000)	(378,000)
Ending Balance		71,000	1,033,000
Change in unrealized gain (losses) still held	[3]	3,000	65,000
Trading securities | Equity securities
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning Balance		29,000	30,000
Gains (losses) in Earnings	[4]		1,000
Purchases			2,000
Sales			(3,000)
Settlements		(1,000)	(1,000)
Ending Balance		28,000	29,000
Change in unrealized gain (losses) still held	[3]	1,000
Derivative financial instruments assets | Interest rate contracts
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning Balance	[5]	8,000	(5,000)
Gains (losses) in Earnings	[4],[5]	11,000	4,000
Settlements	[5]	3,000	9,000
Ending Balance	[5]	22,000	8,000
Change in unrealized gain (losses) still held	[3],[5]	(22,000)	13,000
Derivative financial instruments assets | Foreign exchange contracts
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning Balance	[5]	23,000	16,000
Gains (losses) in Earnings	[4],[5]	8,000	9,000
Settlements	[5]	1,000	(2,000)
Ending Balance	[5]	32,000	23,000
Change in unrealized gain (losses) still held	[3],[5]	7,000	10,000
Derivative financial instruments assets | Equity-related contracts
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning Balance	[5]	(21,000)	(17,000)
Gains (losses) in Earnings	[4],[5]	(11,000)	1,000
Settlements	[5]	18,000	(5,000)
Ending Balance	[5]	(14,000)	(21,000)
Change in unrealized gain (losses) still held	[3],[5]	(23,000)	(17,000)
Derivative financial instruments assets | Credit-related contracts
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning Balance	[5]	2,000	(2,000)
Gains (losses) in Earnings	[4],[5]	(3,000)	4,000
Transfers into Level 3	[5]		1,000
Transfers out of level 3	[5]		1,000
Settlements	[5]	2,000	(2,000)
Ending Balance	[5]	1,000	2,000
Change in unrealized gain (losses) still held	[3],[5]	(1,000)	1,000
Derivative financial instruments assets | Other contracts
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning Balance	[5]		1,000
Gains (losses) in Earnings	[4],[5]	1,000
Settlements	[5]	(1,000)	(1,000)
Available-for-sale securities
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Transfers into Level 3			12,000
Transfers out of level 3		(693,000)	(22,000)
Available-for-sale securities | Residential mortgage-backed securities
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning Balance		23,000	31,000
Settlements		(5,000)	(8,000)
Ending Balance		18,000	23,000
Available-for-sale securities | Commercial mortgage-backed securities
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning Balance		716,000	615,000
Gains (losses) in Earnings	[6]	5,000
Gains (losses) in OCI	[2]	(5,000)	1,000
Transfers out of level 3		(689,000)
Purchases		62,000	181,000
Sales		(60,000)	(78,000)
Settlements		(29,000)	(3,000)
Ending Balance			716,000
Available-for-sale securities | Japanese corporate bonds and other debt securities
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning Balance		365,000	157,000
Gains (losses) in Earnings	[6]	(20,000)	(13,000)
Gains (losses) in OCI	[2]	1,000	6,000
Transfers out of level 3		(4,000)	(22,000)
Purchases		11,000	391,000
Sales			(118,000)
Settlements		(38,000)	(36,000)
Ending Balance		315,000	365,000
Change in unrealized gain (losses) still held	[3]	(19,000)	(8,000)
Available-for-sale securities | Foreign corporate bonds and other debt securities
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning Balance		132,000	174,000
Gains (losses) in Earnings	[6]		7,000
Gains (losses) in OCI	[2]	7,000	16,000
Transfers into Level 3			12,000
Transfers out of level 3		(4,000)
Purchases		47,000	36,000
Settlements		(65,000)	(113,000)
Ending Balance		117,000	132,000
Change in unrealized gain (losses) still held	[3]	1,000
Available-for-sale securities | Other investments
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning Balance		53,000	39,000
Gains (losses) in Earnings	[6]	2,000	2,000
Purchases		37,000	38,000
Sales		(3,000)	(6,000)
Settlements		(33,000)	(20,000)
Ending Balance		56,000	53,000
Change in unrealized gain (losses) still held	[3]	¥ (2,000)	¥ 1,000
[1]Gains (losses) in Earnings are reported in Other noninterest income (expenses).[2]Gains (losses) in OCI are reported in Other comprehensive income (loss).[3]Amounts represent total gains or losses recognized in earnings and OCI during the period. These gains or losses were attributable to the change in fair value relating to assets and liabilities classified as Level 3 that were still held at March 31, 2021 and 2022. The amounts of unrealized gains (losses) in OCI related to Available-for-sale securities and Long-term debt, which were ¥6 billion and ¥(17) billion, respectively, at March 31, 2021, and ¥0 billion and ¥0 billion, respectively, at March 31, 2022.[4]Gains (losses) in Earnings are reported in Trading account gains (losses)—net, Foreign exchange gains (losses)—net or Other noninterest income (expenses).[5]Total Level 3 derivative exposures have been netted on the table for presentation purposes only.[6]Gains (losses) in Earnings are reported in Investment gains (losses)—net.

Fair Value (Reconciliation fo_2

Fair Value (Reconciliation for All Assets and Liabilities Measured at Fair Value on a Recurring Basis Using Significant Unobservable Inputs (Level 3) (Parenthetical) (Detail) - JPY (¥) ¥ in Billions	12 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Fair Value Disclosures [Abstract]
Unrealized gains (losses) in OCI related to Available-for-sale securities	¥ 2	¥ 6
Unrealized gains (losses) in OCI related to Long-term debt	¥ 2	¥ (17)

Fair Value (Quantitative Inform

Fair Value (Quantitative Information about Significant Unobservable Inputs Related to Material Classes of Level 3 Assets and Liabilities) (Detail) ¥ in Millions		Mar. 31, 2022 JPY (¥)	Mar. 31, 2021 JPY (¥)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Long-term debt		¥ 2,756,062	¥ 2,703,021
Available For Sale And Trading Securities | Residential mortgage-backed securities
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Trading securities		26,000	32,000
Available For Sale And Trading Securities | Commercial mortgage-backed securities
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Trading securities			716,000
Available For Sale And Trading Securities | Corporate bonds and other debt securities
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Trading securities		503,000	1,530,000
Derivative Financial Instruments | Other contracts
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivatives financial instruments		0
Derivative Financial Instruments | Interest rate contracts
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivatives financial instruments		22,000	8,000
Derivative Financial Instruments | Foreign exchange contracts
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivatives financial instruments		32,000	23,000
Derivative Financial Instruments | Equity-related contracts
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivatives financial instruments		(14,000)	(21,000)
Derivative Financial Instruments | Credit-related contracts
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivatives financial instruments		1,000	2,000
Long-term debt
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Long-term debt		¥ 794,000	¥ 713,000
Minimum | Measurement Input, Prepayment Rate [Member] | Available For Sale And Trading Securities | Residential mortgage-backed securities | Discounted Cash Flows Valuation Technique [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Trading securities		0	2
Minimum | Measurement Input, Prepayment Rate [Member] | Available For Sale And Trading Securities | Corporate bonds and other debt securities | Discounted Cash Flows Valuation Technique [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Trading securities	[1]	6	10
Minimum | Measurement Input, Default Rate [Member] | Available For Sale And Trading Securities | Residential mortgage-backed securities | Discounted Cash Flows Valuation Technique [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Trading securities		0	0
Minimum | Measurement Input, Default Rate [Member] | Available For Sale And Trading Securities | Corporate bonds and other debt securities | Discounted Cash Flows Valuation Technique [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Trading securities	[1]	0	1
Minimum | Measurement Input, Default Rate [Member] | Derivative Financial Instruments | Credit-related contracts | Internal Valuation Model
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivatives financial instruments	[2]	0	0
Minimum | Measurement Input, Default Rate [Member] | Long-term debt | Internal Valuation Model
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Long-term debt	[2]	0	0
Minimum | Measurement Input Recovery Rate [Member] | Available For Sale And Trading Securities | Residential mortgage-backed securities | Discounted Cash Flows Valuation Technique [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Trading securities		100	100
Minimum | Measurement Input Recovery Rate [Member] | Available For Sale And Trading Securities | Corporate bonds and other debt securities | Discounted Cash Flows Valuation Technique [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Trading securities	[1]	10	10
Minimum | Measurement Input, Discount Rate [Member] | Available For Sale And Trading Securities | Residential mortgage-backed securities | Discounted Cash Flows Valuation Technique [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Trading securities		30	28
Minimum | Measurement Input, Discount Rate [Member] | Available For Sale And Trading Securities | Corporate bonds and other debt securities | Discounted Cash Flows Valuation Technique [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Trading securities	[1]	35	45
Minimum | Measurement Input Discount Rate1 [Member] | Available For Sale And Trading Securities | Commercial mortgage-backed securities | Discounted Cash Flows Valuation Technique [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Trading securities			5
Minimum | Measurement Input Discount Rate1 [Member] | Available For Sale And Trading Securities | Corporate bonds and other debt securities | Discounted Cash Flows Valuation Technique [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Trading securities	[3]	4	4
Minimum | Measurement Input, IR - IR correlation [Member] | Derivative Financial Instruments | Interest rate contracts | Internal Valuation Model
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivatives financial instruments	[2]	23	35
Minimum | Measurement Input, IR - IR correlation [Member] | Long-term debt | Internal Valuation Model
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Long-term debt	[2]	23	49
Minimum | Measurement Input, FX - IR correlation [Member] | Derivative Financial Instruments | Foreign exchange contracts | Internal Valuation Model
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivatives financial instruments	[2]	11	23
Minimum | Measurement Input, FX - IR correlation [Member] | Long-term debt | Internal Valuation Model
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Long-term debt	[2]	11	23
Minimum | Measurement Input, FX - FX correlation [Member] | Derivative Financial Instruments | Foreign exchange contracts | Internal Valuation Model
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivatives financial instruments	[2]	41	43
Minimum | Measurement Input, FX - FX correlation [Member] | Long-term debt | Internal Valuation Model
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Long-term debt	[2]	41	43
Minimum | Measurement Input, Equity - IR correlation [Member] | Derivative Financial Instruments | Equity-related contracts | Internal Valuation Model
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivatives financial instruments	[2]	25	25
Minimum | Measurement Input, Equity - IR correlation [Member] | Long-term debt | Internal Valuation Model
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Long-term debt	[2]	25	25
Minimum | Measurement Input, Equity - FX correlation [Member] | Long-term debt | Internal Valuation Model
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Long-term debt	[2]	(17)	33
Minimum | Measurement Input, Equity volatility [Member] | Derivative Financial Instruments | Equity-related contracts | Internal Valuation Model
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivatives financial instruments	[2]	13	8
Minimum | Measurement Input, Equity volatility [Member] | Long-term debt | Internal Valuation Model
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Long-term debt	[2]	9	8
Minimum | Measurement Input, Credit correlation [Member] | Derivative Financial Instruments | Credit-related contracts | Internal Valuation Model
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivatives financial instruments	[2]	43	40
Minimum | Measurement Input, Credit correlation [Member] | Long-term debt | Internal Valuation Model
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Long-term debt	[2]	19	17
Minimum | Measurement Input, Equity correlation [Member] | Derivative Financial Instruments | Equity-related contracts | Internal Valuation Model
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivatives financial instruments	[2]	3	0
Minimum | Measurement Input, Equity correlation [Member] | Long-term debt | Internal Valuation Model
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Long-term debt	[2]	3	0
Minimum | Measurement Input Commodity Volatility [Member] | Derivative Financial Instruments | Other contracts | Internal Valuation Model
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivatives financial instruments	[2]	0	0
Maximum | Measurement Input, Prepayment Rate [Member] | Available For Sale And Trading Securities | Residential mortgage-backed securities | Discounted Cash Flows Valuation Technique [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Trading securities		18	17
Maximum | Measurement Input, Prepayment Rate [Member] | Available For Sale And Trading Securities | Corporate bonds and other debt securities | Discounted Cash Flows Valuation Technique [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Trading securities	[1]	24	18
Maximum | Measurement Input, Default Rate [Member] | Available For Sale And Trading Securities | Residential mortgage-backed securities | Discounted Cash Flows Valuation Technique [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Trading securities		0	0.01
Maximum | Measurement Input, Default Rate [Member] | Available For Sale And Trading Securities | Corporate bonds and other debt securities | Discounted Cash Flows Valuation Technique [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Trading securities	[1]	60	24
Maximum | Measurement Input, Default Rate [Member] | Derivative Financial Instruments | Credit-related contracts | Internal Valuation Model
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivatives financial instruments	[2]	8	5
Maximum | Measurement Input, Default Rate [Member] | Long-term debt | Internal Valuation Model
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Long-term debt	[2]	8	5
Maximum | Measurement Input Recovery Rate [Member] | Available For Sale And Trading Securities | Residential mortgage-backed securities | Discounted Cash Flows Valuation Technique [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Trading securities		100	1
Maximum | Measurement Input Recovery Rate [Member] | Available For Sale And Trading Securities | Corporate bonds and other debt securities | Discounted Cash Flows Valuation Technique [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Trading securities	[1]	40	68
Maximum | Measurement Input, Discount Rate [Member] | Available For Sale And Trading Securities | Residential mortgage-backed securities | Discounted Cash Flows Valuation Technique [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Trading securities		167	170
Maximum | Measurement Input, Discount Rate [Member] | Available For Sale And Trading Securities | Corporate bonds and other debt securities | Discounted Cash Flows Valuation Technique [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Trading securities	[1]	103	143
Maximum | Measurement Input Discount Rate1 [Member] | Available For Sale And Trading Securities | Commercial mortgage-backed securities | Discounted Cash Flows Valuation Technique [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Trading securities			210
Maximum | Measurement Input Discount Rate1 [Member] | Available For Sale And Trading Securities | Corporate bonds and other debt securities | Discounted Cash Flows Valuation Technique [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Trading securities	[3]	447	507
Maximum | Measurement Input, IR - IR correlation [Member] | Derivative Financial Instruments | Interest rate contracts | Internal Valuation Model
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivatives financial instruments	[2]	100	100
Maximum | Measurement Input, IR - IR correlation [Member] | Long-term debt | Internal Valuation Model
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Long-term debt	[2]	100	100
Maximum | Measurement Input, FX - IR correlation [Member] | Derivative Financial Instruments | Foreign exchange contracts | Internal Valuation Model
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivatives financial instruments	[2]	52	50
Maximum | Measurement Input, FX - IR correlation [Member] | Long-term debt | Internal Valuation Model
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Long-term debt	[2]	52	50
Maximum | Measurement Input, FX - FX correlation [Member] | Derivative Financial Instruments | Foreign exchange contracts | Internal Valuation Model
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivatives financial instruments	[2]	65	65
Maximum | Measurement Input, FX - FX correlation [Member] | Long-term debt | Internal Valuation Model
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Long-term debt	[2]	65	65
Maximum | Measurement Input, Equity - IR correlation [Member] | Derivative Financial Instruments | Equity-related contracts | Internal Valuation Model
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivatives financial instruments	[2]	25	25
Maximum | Measurement Input, Equity - IR correlation [Member] | Long-term debt | Internal Valuation Model
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Long-term debt	[2]	25	25
Maximum | Measurement Input, Equity - FX correlation [Member] | Long-term debt | Internal Valuation Model
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Long-term debt	[2]	17	50
Maximum | Measurement Input, Equity volatility [Member] | Derivative Financial Instruments | Equity-related contracts | Internal Valuation Model
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivatives financial instruments	[2]	121	71
Maximum | Measurement Input, Equity volatility [Member] | Long-term debt | Internal Valuation Model
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Long-term debt	[2]	121	71
Maximum | Measurement Input, Credit correlation [Member] | Derivative Financial Instruments | Credit-related contracts | Internal Valuation Model
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivatives financial instruments	[2]	100	100
Maximum | Measurement Input, Credit correlation [Member] | Long-term debt | Internal Valuation Model
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Long-term debt	[2]	100	100
Maximum | Measurement Input, Equity correlation [Member] | Derivative Financial Instruments | Equity-related contracts | Internal Valuation Model
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivatives financial instruments	[2]	100	100
Maximum | Measurement Input, Equity correlation [Member] | Long-term debt | Internal Valuation Model
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Long-term debt	[2]	100	100
Maximum | Measurement Input Commodity Volatility [Member] | Derivative Financial Instruments | Other contracts | Internal Valuation Model
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivatives financial instruments	[2]	89	63
Weighted Average | Measurement Input, Prepayment Rate [Member] | Available For Sale And Trading Securities | Residential mortgage-backed securities | Discounted Cash Flows Valuation Technique [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Trading securities	[4]	6	7
Weighted Average | Measurement Input, Prepayment Rate [Member] | Available For Sale And Trading Securities | Corporate bonds and other debt securities | Discounted Cash Flows Valuation Technique [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Trading securities	[1],[4]	24	18
Weighted Average | Measurement Input, Default Rate [Member] | Available For Sale And Trading Securities | Residential mortgage-backed securities | Discounted Cash Flows Valuation Technique [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Trading securities	[4]	0	0
Weighted Average | Measurement Input, Default Rate [Member] | Available For Sale And Trading Securities | Corporate bonds and other debt securities | Discounted Cash Flows Valuation Technique [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Trading securities	[1],[4]	1	2
Weighted Average | Measurement Input, Default Rate [Member] | Derivative Financial Instruments | Credit-related contracts | Internal Valuation Model
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivatives financial instruments	[2],[4]	1	1
Weighted Average | Measurement Input, Default Rate [Member] | Long-term debt | Internal Valuation Model
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Long-term debt	[2],[4]	1	1
Weighted Average | Measurement Input Recovery Rate [Member] | Available For Sale And Trading Securities | Residential mortgage-backed securities | Discounted Cash Flows Valuation Technique [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Trading securities	[4]	100	100
Weighted Average | Measurement Input Recovery Rate [Member] | Available For Sale And Trading Securities | Corporate bonds and other debt securities | Discounted Cash Flows Valuation Technique [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Trading securities	[1],[4]	39	66
Weighted Average | Measurement Input, Discount Rate [Member] | Available For Sale And Trading Securities | Residential mortgage-backed securities | Discounted Cash Flows Valuation Technique [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Trading securities	[4]	53	51
Weighted Average | Measurement Input, Discount Rate [Member] | Available For Sale And Trading Securities | Corporate bonds and other debt securities | Discounted Cash Flows Valuation Technique [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Trading securities	[1],[4]	47	115
Weighted Average | Measurement Input Discount Rate1 [Member] | Available For Sale And Trading Securities | Commercial mortgage-backed securities | Discounted Cash Flows Valuation Technique [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Trading securities	[4]		22
Weighted Average | Measurement Input Discount Rate1 [Member] | Available For Sale And Trading Securities | Corporate bonds and other debt securities | Discounted Cash Flows Valuation Technique [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Trading securities	[3],[4]	340	284
Weighted Average | Measurement Input, IR - IR correlation [Member] | Derivative Financial Instruments | Interest rate contracts | Internal Valuation Model
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivatives financial instruments	[2],[4]	75	76
Weighted Average | Measurement Input, IR - IR correlation [Member] | Long-term debt | Internal Valuation Model
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Long-term debt	[2],[4]	75	78
Weighted Average | Measurement Input, FX - IR correlation [Member] | Derivative Financial Instruments | Foreign exchange contracts | Internal Valuation Model
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivatives financial instruments	[2],[4]	31	30
Weighted Average | Measurement Input, FX - IR correlation [Member] | Long-term debt | Internal Valuation Model
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Long-term debt	[2],[4]	39	36
Weighted Average | Measurement Input, FX - FX correlation [Member] | Derivative Financial Instruments | Foreign exchange contracts | Internal Valuation Model
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivatives financial instruments	[2],[4]	53	54
Weighted Average | Measurement Input, FX - FX correlation [Member] | Long-term debt | Internal Valuation Model
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Long-term debt	[2],[4]	53	54
Weighted Average | Measurement Input, Equity - IR correlation [Member] | Derivative Financial Instruments | Equity-related contracts | Internal Valuation Model
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivatives financial instruments	[2],[4]	25	25
Weighted Average | Measurement Input, Equity - IR correlation [Member] | Long-term debt | Internal Valuation Model
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Long-term debt	[2],[4]	25	25
Weighted Average | Measurement Input, Equity - FX correlation [Member] | Long-term debt | Internal Valuation Model
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Long-term debt	[2],[4]	0	0
Weighted Average | Measurement Input, Equity volatility [Member] | Derivative Financial Instruments | Equity-related contracts | Internal Valuation Model
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivatives financial instruments	[2],[4]	47	41
Weighted Average | Measurement Input, Equity volatility [Member] | Long-term debt | Internal Valuation Model
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Long-term debt	[2],[4]	34	29
Weighted Average | Measurement Input, Credit correlation [Member] | Derivative Financial Instruments | Credit-related contracts | Internal Valuation Model
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivatives financial instruments	[2],[4]	66	66
Weighted Average | Measurement Input, Credit correlation [Member] | Long-term debt | Internal Valuation Model
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Long-term debt	[2],[4]	64	68
Weighted Average | Measurement Input, Equity correlation [Member] | Derivative Financial Instruments | Equity-related contracts | Internal Valuation Model
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivatives financial instruments	[2],[4]	90	88
Weighted Average | Measurement Input, Equity correlation [Member] | Long-term debt | Internal Valuation Model
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Long-term debt	[2],[4]	90	88
Weighted Average | Measurement Input Commodity Volatility [Member] | Derivative Financial Instruments | Other contracts | Internal Valuation Model
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivatives financial instruments	[2],[4]	55	33
[1]These inputs are mainly used for determining the fair values of securitization products such as CDO, CLO and ABS, other than RMBS and CMBS.[2]Internal valuation model includes discounted cash flow models and the Black-Scholes option pricing model.[3]This input is mainly used for determining the fair values of Japanese corporate bonds and foreign corporate bonds.[4]Averages are calculated by weighting each input by the relative fair value of the respective financial instruments except for derivative related inputs where medians are used.

Fair Value (Summary of Assets_3

Fair Value (Summary of Assets and Liabilities Measured at Fair Value on a Nonrecurring Basis) (Detail) - JPY (¥) ¥ in Millions	Mar. 31, 2022	Mar. 31, 2021	Mar. 31, 2020
Assets:
Equity securities (without readily determinable fair values)	¥ 207,407	¥ 186,146	¥ 419,775
Fair Value, Measurements, Nonrecurring
Assets:
Loans	81,000	85,000
Loans held-for-sale	76,000	22,000
Equity securities (without readily determinable fair values)	4,000	3,000
Other assets		24,000
Total assets measured at fair value	161,000	134,000
Fair Value, Measurements, Nonrecurring | Aggregate cost
Assets:
Loans	128,000	167,000
Loans held-for-sale	77,000	23,000
Equity securities (without readily determinable fair values)	4,000	4,000
Premises and equipment-net	13,000	7,000
Other assets	3,000	34,000
Total assets measured at fair value	225,000	235,000
Fair Value, Measurements, Nonrecurring | Level 2
Assets:
Loans		3,000
Loans held-for-sale	27,000	21,000
Equity securities (without readily determinable fair values)	3,000
Total assets measured at fair value	30,000	24,000
Fair Value, Measurements, Nonrecurring | Level 3
Assets:
Loans	81,000	82,000
Loans held-for-sale	49,000	1,000
Equity securities (without readily determinable fair values)	1,000	3,000
Other assets		24,000
Total assets measured at fair value	¥ 131,000	¥ 110,000

Fair Value (Carrying Amounts an

Fair Value (Carrying Amounts and Fair Values of Certain Financial Instruments, Excluding Financial Instruments Carried at Fair Value on a Recurring Basis and Those outside Scope of ASC 825) (Detail) - JPY (¥) ¥ in Millions		Mar. 31, 2022	Mar. 31, 2021
Financial liabilities:
Long-term debt		¥ 2,756,062	¥ 2,703,021
Carrying amount
Financial assets:
Cash and due from banks, interest-bearing deposits in other banks, call loans and funds sold, and receivables under resale agreements and securities borrowing transactions		68,366,000	63,910,000
Investments		1,519,000	887,000
Loans, net of allowance for loan losses	[1]	89,264,000	87,708,000
Financial liabilities:
Noninterest-bearing deposits, call money and funds purchased, and payables under repurchase agreements and securities lending transactions		58,054,000	53,278,000
Interest-bearing deposits		121,833,000	118,860,000
Due to trust accounts		390,000	381,000
Other short-term borrowings		7,567,000	9,086,000
Long-term debt		9,849,000	9,034,000
Estimated fair value
Financial assets:
Cash and due from banks, interest-bearing deposits in other banks, call loans and funds sold, and receivables under resale agreements and securities borrowing transactions		68,366,000	63,910,000
Investments		1,466,000	904,000
Loans, net of allowance for loan losses	[1]	90,576,000	88,845,000
Financial liabilities:
Noninterest-bearing deposits, call money and funds purchased, and payables under repurchase agreements and securities lending transactions		58,054,000	53,278,000
Interest-bearing deposits		121,807,000	118,849,000
Due to trust accounts		390,000	381,000
Other short-term borrowings		7,567,000	9,086,000
Long-term debt		9,681,000	9,219,000
Estimated fair value | Level 1
Financial assets:
Cash and due from banks, interest-bearing deposits in other banks, call loans and funds sold, and receivables under resale agreements and securities borrowing transactions		50,628,000	47,441,000
Investments		485,000	490,000
Estimated fair value | Level 2
Financial assets:
Cash and due from banks, interest-bearing deposits in other banks, call loans and funds sold, and receivables under resale agreements and securities borrowing transactions		17,738,000	16,469,000
Investments		981,000	414,000
Financial liabilities:
Noninterest-bearing deposits, call money and funds purchased, and payables under repurchase agreements and securities lending transactions		58,054,000	53,278,000
Interest-bearing deposits		121,807,000	118,849,000
Due to trust accounts		390,000	381,000
Other short-term borrowings		7,567,000	9,086,000
Long-term debt		8,162,000	7,847,000
Estimated fair value | Level 3
Financial assets:
Loans, net of allowance for loan losses	[1]	90,576,000	88,845,000
Financial liabilities:
Long-term debt		¥ 1,519,000	¥ 1,372,000
[1]Loans, net of allowance include items measured at fair value on a nonrecurring basis.

Offsetting of Financial Asset_3

Offsetting of Financial Assets and Financial Liabilities (Information of Offsetting of Financial Assets and Financial Liabilities) (Detail) - JPY (¥) ¥ in Billions		Mar. 31, 2022	Mar. 31, 2021
Offsetting Financial Assets And Financial Liabilities [Line Items]
Derivative assets, Gross amounts recognized	[1]	¥ 9,723	¥ 8,625
Derivative assets, Gross amounts offset on the balance sheet	[1]	0	0
Derivative assets, Net amounts presented on the balance sheet	[1],[2]	9,723	8,625	[3]
Derivative assets, Amounts not offset on the balance sheet, Financial instruments	[1],[4],[5]	(7,232)	(6,323)
Derivative assets, Amounts not offset on the balance sheet, Cash collateral	[1],[4]	(891)	(588)
Derivative assets, Net amounts	[1]	1,600	1,714
Receivables under resale agreements, Gross amounts recognized	[1]	12,751	11,623
Receivables under resale agreements, Gross amounts offset on the balance sheet	[1]	0	0
Receivables under resale agreements, Net amounts presented on the balance sheet	[1],[2]	12,751	11,623	[6]
Receivables under resale agreements, Amounts not offset on the balance sheet, Financial instruments	[1],[4],[5]	(11,437)	(10,478)
Receivables under resale agreements, Amounts not offset on the balance sheet, Cash collateral	[1],[4]	0	0
Receivables under resale agreements, Net amounts	[1]	1,314	1,145
Receivables under securities borrowing transactions, Gross amounts recognized	[1]	2,339	2,694
Receivables under securities borrowing transactions, Gross amounts offset on the balance sheet	[1]	0	0
Receivables under securities borrowing transactions, Net amounts presented on the balance sheet	[1],[2]	2,339	2,694	[7]
Receivables under securities borrowing transactions, Amounts not offset on the balance sheet, Financial instruments	[1],[4],[5]	(2,299)	(2,621)
Receivables under securities borrowing transactions, Amounts not offset on the balance sheet, Cash collateral	[1],[4]	0	0
Receivables under securities borrowing transactions, Net amounts	[1]	40	73
Financial assets, Gross amounts recognized, Total	[1]	24,813	22,942
Financial assets, Gross amounts offset on the balance sheet, Total	[1]	0	0
Financial assets, Net amounts presented on the balance sheet, Total	[1],[2]	24,813	22,942
Financial assets, Amounts not offset on the balance sheet, Financial instruments, Total	[1],[4],[5]	(20,968)	(19,422)
Financial assets, Amounts not offset on the balance sheet, Cash collateral, Total	[1],[4]	(891)	(588)
Financial assets, Net amounts, Total	[1]	2,954	2,932
Derivative liabilities, Gross amounts recognized	[1]	9,770	8,252
Derivative liabilities, Gross amounts offset on the balance sheet	[1]	0	0
Derivative liabilities, Net amounts presented on the balance sheet	[1],[2]	9,770	8,252	[3]
Derivative liabilities, Amounts not offset on the balance sheet, Financial instruments	[1],[4],[5]	(6,716)	(6,033)
Derivative liabilities, Amounts not offset on the balance sheet, Cash collateral	[1],[4]	(1,329)	(933)
Derivative liabilities, Net amounts	[1]	1,725	1,286
Payables under repurchase agreements, Gross amounts recognized	[1]	20,070	18,607
Payables under repurchase agreements, Gross amounts offset on the balance sheet	[1]	0	0
Payables under repurchase agreements, Net amounts presented on the balance sheet	[1],[2]	20,070	18,607	[6]
Payables under repurchase agreements, Amounts not offset on the balance sheet, Financial instruments	[1],[4],[5]	(19,366)	(17,979)
Payables under repurchase agreements, Amounts not offset on the balance sheet, Cash collateral	[1],[4]	0	0
Payables under repurchase agreements, Net amounts	[1]	704	628
Payables under securities lending transactions, Gross amounts recognized	[1]	1,361	1,208
Payables under securities lending transactions, Gross amounts offset on the balance sheet	[1]	0	0
Payables under securities lending transactions, Net amounts presented on the balance sheet	[1],[2]	1,361	1,208	[7]
Payables under securities lending transactions, Amounts not offset on the balance sheet, Financial instruments	[1],[4],[5]	(1,164)	(953)
Payables under securities lending transactions, Amounts not offset on the balance sheet, Cash collateral	[1],[4]	0	0
Payables under securities lending transactions, Net amounts	[1]	197	255
Financial liabilities, Gross amounts recognized, Total	[1]	31,201	28,067
Financial liabilities, Gross amounts offset on the balance sheet, Total	[1]	0	0
Financial liabilities, Net amounts presented on the balance sheet, Total	[1],[2]	31,201	28,067
Financial liabilities, Amounts not offset on the balance sheet, Financial instruments, Total	[1],[4],[5]	(27,246)	(24,965)
Financial liabilities, Amounts not offset on the balance sheet, Cash collateral, Total	[1],[4]	(1,329)	(933)
Financial liabilities, Net amounts, Total	[1]	¥ 2,626	¥ 2,169
[1]Amounts relating to master netting arrangements or similar agreements where the MHFG Group does not have the legal right of set-off or where uncertainty exists as to the enforceability of these agreements are excluded. For derivatives, the table includes amounts relating to over-the-counter (“OTC”) and OTC-cleared derivatives that are subject to enforceable master netting arrangements or similar agreements.[2]Derivative assets and liabilities are recorded in Trading account assets and Trading account liabilities, respectively.[3]The amounts of derivative assets and liabilities subject to enforceable master netting arrangements or similar agreements were ¥8,168 billion and ¥7,652 billion, respectively, at March 31, 2021, and ¥9,326 billion and ¥9,235 billion, respectively, at March 31, 2022.[4]Amounts do not exceed the net amounts presented on the balance sheet and do not include the effect of overcollateralization, where it exists.[5]For derivatives, amounts include derivative assets or liabilities and securities collateral that are eligible for offsetting under enforceable master netting arrangements or similar agreements.[6]The amounts of Receivables under resale agreements and Payables under repurchase agreements subject to enforceable industry standard master repurchase agreements with netting terms were ¥10,551 billion and ¥18,321 billion, respectively, at March 31, 2021, and ¥11,537 billion and ¥19,505 billion respectively, at March 31, 2022.[7]The amounts of Receivables under securities borrowing transactions and Payables under securities lending transactions subject to enforceable industry standard master lending agreements with netting terms were ¥2,694 billion and ¥958 billion, respectively, at March 31, 2021, and ¥2,339 billion and ¥1,172 billion respectively, at March 31, 2022.

Offsetting of Financial Asset_4

Offsetting of Financial Assets and Financial Liabilities (Information of Offsetting of Financial Assets and Financial Liabilities) (Parenthetical) (Detail) - JPY (¥) ¥ in Billions	Mar. 31, 2022	Mar. 31, 2021
Offsetting Financial Assets And Financial Liabilities [Line Items]
Receivables under resale agreement subject to enforceable master netting arrangements	¥ 11,537	¥ 10,551
Payables under repurchase agreement subject to enforceable master netting arrangements	19,505	18,321
Receivables under securities transaction borrowing subject to master netting arrangement	2,339	2,694
Payables under securities transaction lending subject to master netting arragement	1,172	958
Subject To Enforceable Master Netting Arragement [Member]
Offsetting Financial Assets And Financial Liabilities [Line Items]
Derivative assets subject to enforceable master netting arrangements	9,326	8,168
Derivative liabilities subject to enforceable master netting arrangements	¥ 9,235	¥ 7,652

Repurchase Agreements and Sec_3

Repurchase Agreements and Securities Lending Transactions Accounted for as Secured Borrowings (Gross Amounts of Liabilities by Remaining Contractual Maturity) (Detail) - JPY (¥) ¥ in Billions	Mar. 31, 2022	Mar. 31, 2021
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Repurchase agreements	¥ 20,070	¥ 18,607
Securities lending transactions	1,361	1,208
Total	21,431	19,815
Overnight and continuous
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Repurchase agreements	7,011	9,459
Securities lending transactions	1,098	943
Total	8,109	10,402
Up to 30 Days
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Repurchase agreements	10,621	3,586
Securities lending transactions	74	15
Total	10,695	3,601
31 to 90 Days
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Repurchase agreements	1,340	4,315
Securities lending transactions	0
Total	1,340	4,315
Greater than 90 Days
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Repurchase agreements	1,098	1,247
Securities lending transactions	189	250
Total	¥ 1,287	¥ 1,497

Repurchase Agreements and Sec_4

Repurchase Agreements and Securities Lending Transactions Accounted for as Secured Borrowings (Gross Amounts of Liabilities by Class of Underlying Collateral) (Detail) - JPY (¥) ¥ in Billions	Mar. 31, 2022	Mar. 31, 2021
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Repurchase agreements	¥ 20,070	¥ 18,607
Securities lending transactions	1,361	1,208
Japanese government bonds and Japanese local government bonds
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Repurchase agreements	1,714	1,787
Securities lending transactions	217	352
Foreign government bonds and foreign agency mortgage-backed securities
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Repurchase agreements	17,445	15,917
Securities lending transactions	90	131
Commercial Paper and Corporate Bonds
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Repurchase agreements	271	284
Securities lending transactions	52	57
Equity Securities
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Repurchase agreements	609	544
Securities lending transactions	989	654
Other securities
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Repurchase agreements	31	75
Securities lending transactions	¥ 13	¥ 14

Related Party Transactions - Su

Related Party Transactions - Summary of financial information of groups equity method investees (Detail) - JPY (¥) ¥ in Millions	12 Months Ended
	Mar. 31, 2022	Mar. 31, 2021	Mar. 31, 2020
Related Party Transaction [Line Items]
Loans	¥ 90,290,583	¥ 88,580,867
Total assets	231,550,704	221,651,474	¥ 211,218,800
Total liabilities	222,108,473	211,963,317
Total equity	9,442,231	9,688,157	9,175,624
Noncontrolling interests	528,019	582,919
Total interest and dividend income	1,443,941	1,456,556	2,151,172
Total interest expense	374,132	467,939	1,271,381
Provision (credit) for credit losses	214,408	112,776	156,200
Net interest income after provision (credit) for credit losses	855,401	875,841	723,591
Income before income tax expense	(242,488)	1,028,764	153,490
Net income	(101,471)	818,048	106,315
Equity Method Investee
Related Party Transaction [Line Items]
Loans	7,765,000	7,521,000
Total assets	30,180,000	29,540,000
Deposits	8,713,000	10,301,000
Total liabilities	27,474,000	27,247,000
Total equity	2,706,000	2,293,000
Noncontrolling interests	14,000	13,000
Total interest and dividend income	625,000	570,000	586,000
Total interest expense	182,000	188,000	198,000
Provision (credit) for credit losses	104,000	91,000	81,000
Net interest income after provision (credit) for credit losses	339,000	291,000	307,000
Income before income tax expense	332,000	237,000	196,000
Net income	¥ 246,000	¥ 178,000	¥ 150,000

Related Party Transactions - Ad

Related Party Transactions - Additional Information (Detail) ¥ in Billions	12 Months Ended
	Mar. 31, 2022 JPY (¥) Loans	Mar. 31, 2021 JPY (¥) Loans
Related Party Transaction [Line Items]
Number of loans impaired | Loans	0	0
Related party loan | ¥	¥ 604	¥ 550

Business Segment Information -

Business Segment Information - Additional Information (Detail)	12 Months Ended
	Mar. 31, 2022 Segment
Segment Reporting Information [Line Items]
Number of operating segments	5

Business Segment Information (R

Business Segment Information (Reportable Segment Information Derived from Internal Management Reporting Systems, on Basis of Japanese GAAP) (Detail) - JPY (¥) ¥ in Billions		12 Months Ended
		Mar. 31, 2022	Mar. 31, 2021	Mar. 31, 2020
Japan Gaap Schedule of Segment Reporting Information, by Segment [Line Items]
Gross profits + Net gains (losses) related to ETFs and others	[1],[2]	¥ 2,254.5	¥ 2,200.8	¥ 2,072.8
General and administrative expenses	[1],[3]	1,415	1,408.7	1,411.5
Equity in earnings (losses) of equity method investees—net	[1]	25.4	19.9	30.4
Amortization of goodwill and others	[1]	11.7	12.2	13.2
Others	[1]	0	0	(5.9)
Net business profits (losses) + Net gains (losses) related to ETFs and others	[1],[4]	853.2	799.8	672.6
Fixed assets	[1],[5]	1,697.3	1,755.7	1,739.8
Operating Segments | Retail And Business Banking Company
Japan Gaap Schedule of Segment Reporting Information, by Segment [Line Items]
Gross profits + Net gains (losses) related to ETFs and others	[1],[2]	713.7	697.7	693.9
General and administrative expenses	[1],[3]	621	639.6	670.2
Equity in earnings (losses) of equity method investees—net	[1]	5.9	5.5	11.7
Amortization of goodwill and others	[1]	2.2	2.3	2.8
Others	[1]	0	0	0
Net business profits (losses) + Net gains (losses) related to ETFs and others	[1],[4]	96.4	61.3	32.6
Fixed assets	[1],[5]	504.2	543.9	517
Operating Segments | Corporate And Institutional Company
Japan Gaap Schedule of Segment Reporting Information, by Segment [Line Items]
Gross profits + Net gains (losses) related to ETFs and others	[1],[2]	491.7	472.8	440.5
General and administrative expenses	[1],[3]	198.1	206.5	214.8
Equity in earnings (losses) of equity method investees—net	[1]	3.8	3.9	2
Amortization of goodwill and others	[1]	0.1	0.1	0.1
Others	[1]	0	0	0
Net business profits (losses) + Net gains (losses) related to ETFs and others	[1],[4]	297.3	270.1	227.6
Fixed assets	[1],[5]	160.2	193.5	205.7
Operating Segments | Global Corporate Company
Japan Gaap Schedule of Segment Reporting Information, by Segment [Line Items]
Gross profits + Net gains (losses) related to ETFs and others	[1],[2]	518.8	456	417.1
General and administrative expenses	[1],[3]	267.7	259.1	253.4
Equity in earnings (losses) of equity method investees—net	[1]	13.2	10.9	10.4
Amortization of goodwill and others	[1]	0.4	0.4	0.4
Others	[1]	0	0	0
Net business profits (losses) + Net gains (losses) related to ETFs and others	[1],[4]	263.9	207.4	173.7
Fixed assets	[1],[5]	161.5	169.1	168
Operating Segments | Global Markets Company
Japan Gaap Schedule of Segment Reporting Information, by Segment [Line Items]
Gross profits + Net gains (losses) related to ETFs and others	[1],[2]	378.9	490.3	414.5
General and administrative expenses	[1],[3]	227.6	217.7	202.9
Equity in earnings (losses) of equity method investees—net	[1]	0	0	0
Amortization of goodwill and others	[1]	0.8	0.8	1.1
Others	[1]	0	0	0
Net business profits (losses) + Net gains (losses) related to ETFs and others	[1],[4]	150.5	271.8	210.5
Fixed assets	[1],[5]	88.8	98.4	96.8
Operating Segments | Asset Management Company
Japan Gaap Schedule of Segment Reporting Information, by Segment [Line Items]
Gross profits + Net gains (losses) related to ETFs and others	[1],[2]	59.5	50.8	53.3
General and administrative expenses	[1],[3]	33.4	33	33.1
Equity in earnings (losses) of equity method investees—net	[1]	1.4	1.1	1.3
Amortization of goodwill and others	[1]	7.2	7.6	7.8
Others	[1]	0	0	0
Net business profits (losses) + Net gains (losses) related to ETFs and others	[1],[4]	20.3	11.3	13.7
Fixed assets	[1],[5]	0	0	0.1
Others
Japan Gaap Schedule of Segment Reporting Information, by Segment [Line Items]
Gross profits + Net gains (losses) related to ETFs and others	[1],[2]	91.9	33.2	53.5
General and administrative expenses	[1],[3],[6]	67.2	52.8	37.1
Equity in earnings (losses) of equity method investees—net	[1],[6]	1.1	(1.5)	5
Amortization of goodwill and others	[1],[6]	1	1	1
Others	[1],[6]	0	0	(5.9)
Net business profits (losses) + Net gains (losses) related to ETFs and others	[1],[4],[6]	24.8	(22.1)	14.5
Fixed assets	[1],[5],[6]	¥ 782.6	¥ 750.8	¥ 752.2
[1]Income and expenses of foreign branches of MHBK and foreign subsidiaries with functional currencies other than Japanese Yen have been translated for purposes of segment reporting using the budgeted foreign currency rates. Prior period comparative amounts for such foreign currency income and expenses have been translated using current period budgeted foreign currency rates.[2]“Gross profits + Net gains (losses) related to ETFs and others” is reported instead of sales reported by general corporations. Gross profits is defined as the sum of net interest income, fiduciary income, net fee and commission income, net trading income and net other operating income. Net gains (losses) related to ETFs and others consist of net gains (losses) on ETFs held by MHBK and MHTB on their non-consolidated basis and net gains (losses) on operating investment securities of MHSC on its consolidated basis. For the fiscal years ended March 31, 2020, 2021 and 2022,net gains (losses) related to ETFs and others amounted to ¥10.6 billion, ¥2.0 billion and ¥1.9 billion, respectively, of which ¥7.3 billion, ¥(1.3) billion and ¥2.3 billion are included in “Global Markets Company,” respectively.[3]“General and administrative expenses” excludes non-allocated gains (losses), net.[4]Net business profits (losses) is used in Japan as a measure of the profitability of core banking operations, and is defined as gross profits (as defined above) less general and administrative expenses (excluding non-allocated gains (losses), net) plus equity in earnings (losses) of equity method investees—net and others. Measurement of net business profits (losses) is required for regulatory reporting to the Financial Services Agency of Japan.[5]“Fixed assets” is presented based on Japanese GAAP and corresponds to the total amount of the following U.S. GAAP accounts: Premises and equipment-net; Goodwill; Intangible assets; and right-of-use assets related to operating leases included in Other assets. The above table does not include other asset amounts because “Fixed assets” is the only balance sheet metric that management uses when evaluating and making decisions pertaining to the operating segments. “Others” in “Fixed assets” includes assets of headquarters that have not been allocated to each segment, “Fixed assets” pertaining to consolidated subsidiaries that are not subject to allocation, consolidating adjustments, and others. Certain “Fixed assets” expenses have been allocated to each segment using reasonable allocation criteria.[6]“Others” includes the following items: •profits and expenses pertaining to consolidated subsidiaries that are not subject to allocation; •consolidating adjustments, including elimination of internal transaction between each segment; •equity in earnings (losses) of equity method investees-net that are not subject to allocation; and •profits and losses pertaining to derivative transactions that reflect the counterparty risk of the individual parties and other factors in determining fair market value.

Business Segment Information _2

Business Segment Information (Reportable Segment Information Derived from Internal Management Reporting Systems, on Basis of Japanese GAAP) (Parenthetical) (Detail) - JPY (¥) ¥ in Billions		12 Months Ended
		Mar. 31, 2022	Mar. 31, 2021	Mar. 31, 2020
Japan Gaap Schedule of Segment Reporting Information, by Segment [Line Items]
Gross profits and net gains (losses) related to ETFs and others	[1],[2]	¥ 2,254.5	¥ 2,200.8	¥ 2,072.8
Exchange Traded Funds
Japan Gaap Schedule of Segment Reporting Information, by Segment [Line Items]
Gross profits and net gains (losses) related to ETFs and others		1.9	2	10.6
Global Markets Company | Exchange Traded Funds
Japan Gaap Schedule of Segment Reporting Information, by Segment [Line Items]
Gross profits and net gains (losses) related to ETFs and others		¥ 2.3	¥ (1.3)	¥ 7.3
[1]Income and expenses of foreign branches of MHBK and foreign subsidiaries with functional currencies other than Japanese Yen have been translated for purposes of segment reporting using the budgeted foreign currency rates. Prior period comparative amounts for such foreign currency income and expenses have been translated using current period budgeted foreign currency rates.[2]“Gross profits + Net gains (losses) related to ETFs and others” is reported instead of sales reported by general corporations. Gross profits is defined as the sum of net interest income, fiduciary income, net fee and commission income, net trading income and net other operating income. Net gains (losses) related to ETFs and others consist of net gains (losses) on ETFs held by MHBK and MHTB on their non-consolidated basis and net gains (losses) on operating investment securities of MHSC on its consolidated basis. For the fiscal years ended March 31, 2020, 2021 and 2022,net gains (losses) related to ETFs and others amounted to ¥10.6 billion, ¥2.0 billion and ¥1.9 billion, respectively, of which ¥7.3 billion, ¥(1.3) billion and ¥2.3 billion are included in “Global Markets Company,” respectively.

Business Segment Information _3

Business Segment Information (Reconciliation of Total Net Business Profits under Internal Management Reporting Systems to Income Before Income Tax Expense on Consolidated Statements of Income) (Detail) - JPY (¥) ¥ in Millions		12 Months Ended
		Mar. 31, 2022	Mar. 31, 2021	Mar. 31, 2020
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Net business profits (losses) + Net gains (losses) related to ETFs and others		¥ 853,200	¥ 799,800	¥ 672,600
Adjustment to reconcile management reporting to Japanese GAAP:
General and administrative expenses: non-allocated gains (losses), net		33,700	6,300	46,300
Expenses related to portfolio problems (including reversal of (provision for) general reserve for losses on loans)		(255,900)	(209,900)	(183,300)
Gains on reversal of reserves for possible losses on loans, and others		20,800	4,900	11,600
Net gains (losses) related to stocks—Net gains (losses) related to ETFs and others		(45,800)	10,100	126,600
Net extraordinary gains (losses)		44,000	115,900	(19,200)
Others		(46,100)	(74,900)	(35,900)
Income before income tax expense under Japanese GAAP		603,900	652,200	618,700
Adjustment to reconcile Japanese GAAP to U.S. GAAP:
Derivative financial instruments and hedging activities		(124,000)	(86,400)	111,200
Investments		(600,100)	523,500	(480,900)
Loans		(18,300)	(16,900)	(3,000)
Allowances for credit losses	[1]	51,500	83,300	700
Premises and equipment		(68,500)	(56,500)	(96,100)
Land revaluation		6,400	6,400	2,100
Business combinations		6,900	(1,000)	6,000
Pension liabilities		(94,400)	(153,200)	(56,700)
Consolidation of variable interest entities		42,300	104,600	39,300
Foreign currency translation		(51,000)	(31,500)	17,300
Others		2,800	4,300	(5,100)
Income (loss) before income tax expense		¥ (242,488)	¥ 1,028,764	¥ 153,490
[1]The MHFG Group adopted ASU No.2016-13, 2019-04, 2019-05, and 2019-11 on April 1, 2020. Allowances for credit losses for the fiscal year ended March 31, 2021 substitute allowances for loan losses and off-balance-sheet instruments for the fiscal years ended March 31, 2020.

Business Segment Information _4

Business Segment Information (Reconciliation of Assets from Segment to Consolidated) (Detail) - JPY (¥) ¥ in Billions		12 Months Ended
		Mar. 31, 2022	Mar. 31, 2021	Mar. 31, 2020
Schedule Of Assets By Segment [Line Items]
Fixed assets	[1],[2]	¥ 1,697.3	¥ 1,755.7	¥ 1,739.8
U.S. GAAP adjustments	[3]	717.6	816.1	887.2
Premises and equipment-net, Goodwill, Intangible assets, and right-of-use assets related to operating leases included in Other assets		¥ 2,414.9	¥ 2,571.8	¥ 2,627
[1]Income and expenses of foreign branches of MHBK and foreign subsidiaries with functional currencies other than Japanese Yen have been translated for purposes of segment reporting using the budgeted foreign currency rates. Prior period comparative amounts for such foreign currency income and expenses have been translated using current period budgeted foreign currency rates.[2]“Fixed assets” is presented based on Japanese GAAP and corresponds to the total amount of the following U.S. GAAP accounts: Premises and equipment-net; Goodwill; Intangible assets; and right-of-use assets related to operating leases included in Other assets. The above table does not include other asset amounts because “Fixed assets” is the only balance sheet metric that management uses when evaluating and making decisions pertaining to the operating segments. “Others” in “Fixed assets” includes assets of headquarters that have not been allocated to each segment, “Fixed assets” pertaining to consolidated subsidiaries that are not subject to allocation, consolidating adjustments, and others. Certain “Fixed assets” expenses have been allocated to each segment using reasonable allocation criteria.[3]The U.S. GAAP adjustments are primarily comprised of GAAP differences mainly from right-of-use assets related to operating leases not recognized under Japanese GAAP; internally developed software, which was impaired under Japanese GAAP; land, which was revalued under Japanese GAAP; and the consolidation of certain variable interest entities, which are not consolidated under Japanese GAAP.

Foreign Activities (Consolidate

Foreign Activities (Consolidated Income Statement and Total Assets Information by Major Geographic Area) (Detail) - JPY (¥) ¥ in Millions		12 Months Ended
		Mar. 31, 2022	Mar. 31, 2021	Mar. 31, 2020
Segment Reporting Information [Line Items]
Total revenue	[1]	¥ 2,113,700	¥ 3,497,900	¥ 3,458,900
Total expenses	[2]	2,356,200	2,469,100	3,305,400
Income (loss) before income tax expense (benefit)		(242,488)	1,028,764	153,490
Net income (loss)		(101,471)	818,048	106,315
Total assets		231,550,704	221,651,474	211,218,800
Japan
Segment Reporting Information [Line Items]
Total revenue	[1]	991,100	2,290,800	1,681,000
Total expenses	[2]	1,713,800	1,918,200	2,008,900
Income (loss) before income tax expense (benefit)		(722,700)	372,600	(327,900)
Net income (loss)		(509,000)	235,600	(312,800)
Total assets		155,111,200	152,613,700	137,470,400
United States of America
Segment Reporting Information [Line Items]
Total revenue	[1]	562,900	503,800	801,500
Total expenses	[2]	265,000	243,500	679,200
Income (loss) before income tax expense (benefit)		297,900	260,300	122,300
Net income (loss)		275,200	227,400	100,400
Total assets		36,765,700	31,939,900	34,650,400
Others
Segment Reporting Information [Line Items]
Total revenue	[1]	41,700	154,500	95,100
Total expenses	[2]	19,000	14,400	41,500
Income (loss) before income tax expense (benefit)		22,700	140,100	53,600
Net income (loss)		18,300	137,200	51,500
Total assets		3,667,900	4,405,300	4,137,300
Europe
Segment Reporting Information [Line Items]
Total revenue	[1]	184,800	188,700	270,400
Total expenses	[2]	189,200	115,800	239,100
Income (loss) before income tax expense (benefit)		(4,400)	72,900	31,300
Net income (loss)		(16,300)	60,900	23,600
Total assets		15,795,900	14,150,600	15,487,000
Asia/Oceania excluding Japan, and others
Segment Reporting Information [Line Items]
Total revenue	[1]	333,200	360,100	610,900
Total expenses	[2]	169,200	177,200	336,700
Income (loss) before income tax expense (benefit)		164,000	182,900	274,200
Net income (loss)		130,300	156,900	243,600
Total assets		¥ 20,210,000	¥ 18,542,000	¥ 19,473,700
[1]Total revenue is comprised of Interest and dividend income and Noninterest income.[2]Total expenses are comprised of Interest expense, Provision (credit) for credit losses and Noninterest expenses.

Mizuho Financial Group, Inc.,_3

Mizuho Financial Group, Inc., Parent Company (Condensed Balance Sheets) (Detail) - JPY (¥) ¥ in Millions	Mar. 31, 2022	Mar. 31, 2021	Mar. 31, 2020
Assets:
Cash and due from banking subsidiaries	¥ 2,290,377	¥ 1,600,555
Interest-bearing deposits in banking subsidiaries	49,883,912	47,133,541
Other	8,987,242	7,457,028
Total assets	231,550,704	221,651,474	¥ 211,218,800
Liabilities and shareholders' equity:
Long-term debt	12,578,216	11,706,471
Other liabilities	6,260,222	7,208,758
Shareholders' equity	8,914,212	9,105,238
Total liabilities and equity	231,550,704	221,651,474
Parent Company
Assets:
Cash and due from banking subsidiaries	51,356	44,619
Interest-bearing deposits in banking subsidiaries	414	347
Other	648,946	549,068
Total assets	18,023,008	18,249,061
Liabilities and shareholders' equity:
Short-term borrowings from a banking subsidiary	755,000	850,000
Long-term debt	7,957,710	7,875,414
Other liabilities	396,086	418,409
Shareholders' equity	8,914,212	9,105,238
Total liabilities and equity	18,023,008	18,249,061
Parent Company | Banking Subsidiaries
Assets:
Investments in subsidiaries and affiliated companies	8,102,149	8,561,350
Long-term loans receivable from subsidiaries	7,942,367	7,851,894
Parent Company | Non Banking Subsidiaries And Affiliated Companies
Assets:
Investments in subsidiaries and affiliated companies	878,776	1,241,783
Long-term loans receivable from subsidiaries	¥ 399,000	¥ 0

Mizuho Financial Group, Inc.,_4

Mizuho Financial Group, Inc., Parent Company (Condensed Statements of Income) (Detail) - JPY (¥) ¥ in Millions		12 Months Ended
		Mar. 31, 2022	Mar. 31, 2021	Mar. 31, 2020
Income:
Gains on disposal of premises and equipment		¥ 9,943	¥ 7,125	¥ 2,583
Total	[1]	2,113,700	3,497,900	3,458,900
Expenses:
Interest expense		374,132	467,939	1,271,381
Equity in undistributed net income (loss) of subsidiaries	[2]	34,587	31,027	34,012
Income tax expense (benefit)		(141,017)	210,716	47,175
Net income (loss) attributable to MHFG shareholders		(104,722)	581,765	150,195
Parent Company
Income:
Management fees from subsidiaries		40,462	36,334	38,004
Interest income on loans and discounts		133,215	128,697	123,354
Gains on disposal of premises and equipment		0		10,866
Gains on sales of investments in subsidiaries		53,005	40
Other income		11,319	11,970	7,088
Total		517,823	409,013	215,986
Expenses:
Operating expenses		43,192	37,979	38,951
Interest expense		130,453	130,812	126,516
Losses on sales of investments in a subsidiary		26,606
Other expense		5,946	8,842	25,313
Total		206,197	177,633	190,780
Equity in undistributed net income (loss) of subsidiaries		(505,891)	341,369	130,930
Income (loss) before income tax expense (benefit)		(194,265)	572,749	156,136
Income tax expense (benefit)		(89,543)	(9,016)	5,941
Net income (loss) attributable to MHFG shareholders		(104,722)	581,765	150,195
Parent Company | Banking Subsidiary
Income:
Banking subsidiaries		197,717	214,473	23,824
Parent Company | Non Banking Subsidiaries And Affiliated Companies
Income:
Banking subsidiaries		¥ 82,105	¥ 17,499	¥ 12,850
[1]Total revenue is comprised of Interest and dividend income and Noninterest income.[2]These amounts are revenues from contracts that do not meet the scope of ASC 606.

Mizuho Financial Group, Inc.,_5

Mizuho Financial Group, Inc., parent company (Condensed statements of cash flows) (Detail) - JPY (¥) ¥ in Millions	12 Months Ended
	Mar. 31, 2022	Mar. 31, 2021	Mar. 31, 2020
Cash flows from operating activities:
Net income (loss)	¥ (104,722)	¥ 581,765	¥ 150,195
Net cash provided by operating activities	5,498,087	468,756	(4,041,072)
Cash flows from investing activities:
Purchases of premises and equipment	(136,238)	(211,495)	(243,022)
Net cash provided by (used in) investing activities	(5,016,128)	(2,613,292)	(11,807,589)
Cash flows from financing activities:
Net change in short-term borrowings	(1,711,421)	4,085,165	2,936,677
Proceeds from issuance of long-term debt	3,004,293	2,568,730	2,303,803
Repayment of long-term debt	(2,715,054)	(1,511,050)	(3,273,353)
Purchases of treasury stock	(1,927)	(1,849)	(1,441)
Net cash provided by (used in) financing activities	1,991,438	8,691,908	12,356,954
Parent Company
Cash flows from operating activities:
Net income (loss)	(104,722)	581,765	150,195
Adjustments and other	351,484	(390,748)	(92,059)
Net cash provided by operating activities	246,762	191,017	58,136
Cash flows from investing activities:
Net change in loans	(72,313)	(1,167,385)	(1,496,047)
Purchases of premises and equipment	(26)	(41,382)	(43,406)
Proceeds from sales of premises and equipment	11	55,624	209,657
Proceeds from sales of investments in subsidiaries	452,500	125	245
Net change in other investing activities	223	(1,370)	(5,395)
Net cash provided by (used in) investing activities	380,395	(1,154,388)	(1,334,946)
Cash flows from financing activities:
Net change in short-term borrowings	(95,000)	(10,000)	(85,505)
Proceeds from issuance of long-term debt	930,033	1,477,385	1,531,047
Repayment of long-term debt	(1,256,720)	(310,000)	(35,000)
Purchases of treasury stock	(1,927)	(1,849)	(1,441)
Dividends paid	(196,783)	(190,498)	(190,386)
Net change in other financing activities	44	65	962
Net cash provided by (used in) financing activities	(620,353)	965,103	1,219,677
Net increase (decrease) in cash and cash equivalents	6,804	1,732	(57,133)
Cash and cash equivalents at beginning of fiscal year	44,966	43,234	100,367
Cash and cash equivalents at end of fiscal year	¥ 51,770	¥ 44,966	¥ 43,234