Nippon Steel (NPSCY) 20-F/A 30 Jul 19 2018 FY Annual report (foreign) (amended) Financial data

Document and Entity Information

Document and Entity Information	12 Months Ended
	Mar. 31, 2019shares
Document and entity information [abstract]
Document Type	20-F
Amendment Flag	false
Document Period End Date	Mar. 31, 2019
Document Fiscal Year Focus	2018
Document Fiscal Period Focus	FY
Entity Registrant Name	Nippon Steel Corporation
Entity Central Index Key	0001140471
Current Fiscal Year End Date	--03-31
Entity Well-known Seasoned Issuer	No
Entity Current Reporting Status	Yes
Document Annual Report	true
Document Transition Report	false
Document Shell Company Report	false
Entity Interactive Data Current	Yes
Entity Voluntary Filers	No
Entity Emerging Growth Company	false
Entity Shell Company	false
Security Reporting Obligation	15(d)
Entity Filer Category	Non-accelerated Filer
Entity Common Stock, Shares Outstanding	950,321,402

Consolidated Statements of Fina

Consolidated Statements of Financial Position - JPY (¥) ¥ in Millions	Mar. 31, 2019	Mar. 31, 2018
Current assets
Cash and cash equivalents	¥ 163,176	¥ 142,869
Trade and other receivables	968,333	832,040
Inventories	1,567,116	1,399,821
Other financial assets	16,915	19,178
Other current assets	143,669	139,066
Total current assets	2,859,211	2,532,977
Non-current assets
Property, plant and equipment	3,246,669	3,123,857
Goodwill	52,803	42,263
Intangible assets	106,131	97,131
Investments accounted for using the equity method	793,146	799,239
Other financial assets	812,668	1,007,627
Defined benefit assets	82,247	109,010
Deferred tax assets	88,357	34,944
Other non-current assets	8,292	9,082
Total non-current assets	5,190,316	5,223,157
Total assets	8,049,528	7,756,134
Current liabilities
Trade and other payables	1,611,403	1,580,597
Bonds, borrowings and lease liabilities	515,355	505,384
Other financial liabilities	1,017	674
Income taxes payable	38,719	45,350
Other current liabilities	34,042	28,189
Total current liabilities	2,200,538	2,160,194
Non-current liabilities
Bonds, borrowings and lease liabilities	1,853,876	1,652,371
Other financial liabilities	6,501	6,572
Defined benefit liabilities	186,755	173,619
Deferred tax liabilities	28,253	95,351
Other non-currentliabilities	166,235	143,127
Total non-currentliabilities	2,241,622	2,071,043
Total liabilities	4,442,160	4,231,238
Equity
Common stock	419,524	419,524
Capital surplus	393,917	386,867
Retained earnings	2,300,175	2,141,658
Treasury stock	(58,831)	(132,162)
Other components of equity	176,000	321,101
Total equity attributable to owners of the parent	3,230,788	3,136,991
Non-controllinginterests	376,579	387,905
Total equity	3,607,367	3,524,896
Total liabilities and equity	¥ 8,049,528	¥ 7,756,134

Consolidated Statements of Prof

Consolidated Statements of Profit or Loss - JPY (¥) ¥ in Millions	12 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Mar. 31, 2017
Profit or loss [abstract]
Revenue	¥ 6,177,947	¥ 5,712,965	¥ 4,696,828
Cost of sales	(5,391,493)	(4,948,883)	(4,085,651)
Gross profit	786,453	764,082	611,176
Selling, general and administrative expenses	(568,409)	(533,787)	(466,351)
Share of profit in investments accounted for using the equity method	86,411	65,657	44,118
Other operating income	102,606	91,521	62,108
Other operating expenses	(70,120)	(98,773)	(81,171)
Business profit	336,941	288,700	169,878
Losses on natural disaster	(22,349)
Gains or losses from reorganization	(49,480)		40,165
Operating profit	265,111	288,700	210,044
Finance income	6,104	7,644	6,322
Finance costs	(22,445)	(24,584)	(21,586)
Profit before income taxes	248,769	271,760	194,780
Income tax expense	8,809	(59,549)	(40,297)
Profit for the year	257,579	212,210	154,483
Profit for the year attributable to:
Owners of the parent	251,169	180,832	137,246
Non-controllinginterests	¥ 6,409	¥ 31,377	¥ 17,237
Earnings per share
Basic earnings per share (Yen)	¥ 281.77	¥ 204.87	¥ 155.08

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income or Loss - JPY (¥) ¥ in Millions	12 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Mar. 31, 2017
Statement of comprehensive income [abstract]
Profit for the year	¥ 257,579	¥ 212,210	¥ 154,483
Other comprehensive income
Changes in fair value of financial assets measured at fair value through other comprehensive income	(104,557)	65,222	86,269
Remeasurements of defined benefit plans	(3,531)	19,422	24,063
Share of other comprehensive income of investments accounted for using the equity method	(2,953)	5,125	406
Subtotal	(111,042)	89,770	110,740
Changes in fair value of cash flow hedges	1,522	1,788	9,452
Foreign exchange differences on translation of foreign operations	(41,256)	10,592	(25,079)
Share of other comprehensive income of investments accounted for using the equity method	(21,687)	(2,602)	9,863
Subtotal	(61,421)	9,778	(5,763)
Total other comprehensive income, net of tax	(172,464)	99,548	104,977
Total comprehensive income for the year	85,114	311,759	259,460
Owners of the parent	84,126	272,150	243,122
Non-controllinginterests	988	39,609	16,338
Total comprehensive income for the year	¥ 85,114	¥ 311,759	¥ 259,460

Consolidated Statements of Chan

Consolidated Statements of Changes in Equity - JPY (¥) ¥ in Millions	Total	Common Stock [member]	Capital surplus [member]	Equity attributable Retained earnings [member]	Treasury stock [member]	Changes in fair value of financial assets measured at fair value through other comprehensive income [member]	Remeasurements of defined benefit plans [member]	Changes in fair value of cash flow hedges [member]	Foreign exchange differences on translation of foreign operations [member]	Accumulated other comprehensive income [member]	Equity attributable to owners of parent [member]	Non-controlling interests [member]
Beginning Balance at Mar. 31, 2016	¥ 2,989,195	¥ 419,524	¥ 383,010	¥ 1,838,449	¥ (87,942)	¥ 209,590		¥ (20,704)		¥ 188,886	¥ 2,741,929	¥ 247,266
Comprehensive income
Profit for the year	154,483			137,246							137,246	17,237
Other comprehensive income	104,977					84,690	¥ 21,853	11,450	¥ (12,117)	105,875	105,875	(898)
Total comprehensive income	259,460			137,246		84,690	21,853	11,450	(12,117)	105,875	243,122	16,338
Transactions with owners and others
Cash dividends	(18,886)			(13,554)							(13,554)	(5,332)
Purchases of treasury stock	(44,321)				(44,321)						(44,321)
Disposals of treasury stock	182		(17)		199						182
Changes in ownership interests in subsidiaries	2,742		3,876								3,876	(1,133)
Transfer from other components of equity to retained earnings				38,194		(16,341)	(21,853)			(38,194)
Business combinations and others	98,934				0						0	98,934
Subtotal	38,651		3,858	24,640	(44,121)	(16,341)	(21,853)			(38,194)	(53,816)	92,467
Ending Balance at Mar. 31, 2017	3,287,307	419,524	386,869	2,000,336	(132,063)	277,939		(9,253)	(12,117)	256,568	2,931,234	356,072
Comprehensive income
Profit for the year	212,210			180,832							180,832	31,377
Other comprehensive income	99,548					63,963	19,581	2,653	5,118	91,317	91,317	8,231
Total comprehensive income	311,759			180,832		63,963	19,581	2,653	5,118	91,317	272,150	39,609
Transactions with owners and others
Cash dividends	(73,700)			(66,293)							(66,293)	(7,406)
Purchases of treasury stock	(102)				(102)						(102)
Disposals of treasury stock	4		1		3						4
Changes in ownership interests in subsidiaries	(769)		(3)								(3)	(766)
Transfer from other components of equity to retained earnings				26,783		(7,201)	(19,581)			(26,783)
Business combinations and others	397				0						0	396
Subtotal	(74,170)		(1)	(39,510)	(98)	(7,201)	(19,581)			(26,783)	(66,393)	(7,776)
Ending Balance at Mar. 31, 2018	3,524,896	419,524	386,867	2,141,658	(132,162)	334,701		(6,600)	(6,998)	321,101	3,136,991	387,905
Comprehensive income
Profit for the year	257,579			251,169							251,169	6,409
Other comprehensive income	(172,464)					(104,254)	(4,369)	2,166	(60,586)	(167,043)	(167,043)	(5,420)
Total comprehensive income	85,114			251,169		(104,254)	(4,369)	2,166	(60,586)	(167,043)	84,126	988
Transactions with owners and others
Cash dividends	(78,315)			(70,710)							(70,710)	(7,604)
Purchases of treasury stock	(82)				(82)						(82)
Disposals of treasury stock	72,228		(1,427)		73,656						72,228
Changes in ownership interests in subsidiaries	(85,614)		8,477								8,477	(94,092)
Transfer from other components of equity to retained earnings				(21,942)		17,573	4,369			21,942
Business combinations and others	89,140				(242)						(242)	89,383
Subtotal	(2,643)		7,050	(92,652)	73,331	17,573	¥ 4,369			21,942	9,670	(12,314)
Ending Balance at Mar. 31, 2019	¥ 3,607,367	¥ 419,524	¥ 393,917	¥ 2,300,175	¥ (58,831)	¥ 248,020		¥ (4,433)	¥ (67,585)	¥ 176,000	¥ 3,230,788	¥ 376,579

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - JPY (¥) ¥ in Millions	12 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Mar. 31, 2017
Cash flows from operating activities
Profit before income taxes	¥ 248,769	¥ 271,760	¥ 194,780
Depreciation and amortization	408,616	366,565	330,912
Finance income	(6,104)	(7,644)	(6,322)
Finance costs	22,445	24,584	21,586
Share of profit in investments accounted for using the equity method	(86,411)	(65,657)	(44,118)
Gains on sale of property, plant and equipment and intangible assets	(5,801)	(9,312)	(6,223)
Gains or losses from reorganization	49,480		(40,165)
(Increase) decrease in trade and other receivables	(114,662)	931	(45,605)
(Increase) decrease in inventories	(129,483)	(165,166)	24,001
Increase in trade and other payables	81,058	92,326	57,627
Other, net	21,640	18,674	50,193
Subtotal	489,547	527,062	536,667
Interest received	5,796	5,644	6,326
Dividends received	57,088	45,775	28,773
Interest paid	(19,278)	(26,506)	(20,435)
Income taxes paid	(80,811)	(66,435)	(44,396)
Net cash flows provided by operating activities	452,341	485,539	506,935
Cash flows from investing activities
Purchases of property, plant and equipment and intangible assets	(438,758)	(411,926)	(329,086)
Proceeds from sales of property, plant and equipment and intangible assets	12,841	13,908	15,334
Purchases of investment securities	(8,362)	(3,169)	(48,715)
Proceeds from sales of investment securities	87,693	39,936	42,619
Purchases of investments in associates	(2,787)	(4,940)	(14,783)
Proceeds from sales of investments in associates	5,348	9,522	31,282
Purchases of shares of subsidiaries resulting in change in scope of consolidation	(35,658)	289	(52,892)
Proceeds from sales of shares of subsidiaries resulting in change in scope of consolidation	3,575	473	13,019
Loans to associates and others	(11,870)	(6,688)	(9,711)
Collection of loans from associates and others	3,948	2,878	2,689
Other, net	2,223	(3,455)	(2,338)
Net cash flows used in investing activities	(381,805)	(363,170)	(352,582)
Cash flows from financing activities
Increase/(decrease) in short-term borrowings, net	44,401	(7,114)	(48,189)
Increase in commercial paper, net	23,000	57,140	20,800
Proceeds from long-term borrowings	285,857	247,507	179,432
Repayments of long-term borrowings	(183,006)	(244,835)	(273,476)
Proceeds from issuance of bonds	60,000	40,000	20,000
Redemption of bonds	(85,700)	(140,000)	(50,000)
Increase/(decrease) in factored receivables to group company, net	(85,614)	27,369	75,969
Purchases of treasury stock	(55)	(96)	(44,315)
Cash dividends paid	(70,710)	(66,293)	(13,554)
Dividends paid to non-controlling interests	(7,604)	(7,406)	(5,332)
Proceeds from share issuance to non-controlling shareholders			2,696
Payments for changes in ownership interests in subsidiaries that do not result in change in scope of consolidation	(4,874)	(740)	(650)
Other, net	(18,592)	(10,500)	(11,483)
Net cash flows used in financing activities	(42,900)	(104,969)	(148,103)
Effect of exchange rate changes on cash and cash equivalents	(7,328)	1,540	(3,503)
Net increase in cash and cash equivalents	20,306	18,940	2,745
Cash and cash equivalents at beginning of the year	142,869	123,929	121,183
Cash and cash equivalents at end of the year	¥ 163,176	¥ 142,869	¥ 123,929

Reporting Entity

Reporting Entity	12 Months Ended
	Mar. 31, 2019
Text block [abstract]
Reporting Entity	1. Reporting Entity Nippon Steel Corporation (hereinafter referred to as the “Company” or “NSC”) is a corporation domiciled in Japan. The consolidated financial statements are composed of the Company and its consolidated subsidiaries. The principal businesses of the Company and its subsidiaries (collectively hereinafter referred to as the “Group”) consist of steelmaking and steel fabrication business, engineering and construction business, chemicals & materials business, and system solutions business. The details are described in Note 7 “Segment Information”. On April 1, 2019, Nippon Steel & Sumitomo Metal Corporation changed its corporate name to Nippon Steel Corporation.

Basis of Preparation

Basis of Preparation	12 Months Ended
	Mar. 31, 2019
Text block [abstract]
Basis of Preparation	2. Basis of Preparation (1) Compliance with International Financial Reporting Standards The Company’s consolidated financial statements have been prepared in accordance with International Financial Reporting Standards (“IFRS”), as issued by the International Accounting Standards Board (“IASB”). The term IFRS also includes International Accounting Standards (“IAS”) and the related interpretations of the interpretations committees (“SIC” and” IFRIC”). (2) Basis of measurement The consolidated financial statements have been prepared on the historical cost basis except for certain assets and liabilities as separately stated in Note 3 “Significant Accounting Policies”. (3) Functional currency and presentation currency The consolidated financial statements are presented in Japanese yen, which is the functional currency of the Company. All amounts have been truncated to the nearest millions of Japanese yen, unless otherwise indicated. (4) Authorization of the consolidated financial statements The consolidated financial statements were authorized for issuance by Eiji Hashimoto, Representative Director and President of the Company on July 11, 2019.

Significant Accounting Policies

Significant Accounting Policies	12 Months Ended
	Mar. 31, 2019
Text block [abstract]
Significant Accounting Policies	3. Significant Accounting Policies (1) Basis of consolidation (a) Subsidiaries Subsidiaries are entities controlled by the Group. The Group controls an entity when it is exposed, or has rights to, variable returns from its involvement with the entity and has the ability to affect those returns through its power over the entity. The financial statements of subsidiaries are included in the consolidated financial statements from the date when control is obtained until the date when control is lost. If the Group loses control of a subsidiary, any gain or loss resulting from the loss of control is recognized in profit or loss. Changes in the Group’s interest in a subsidiary not resulting in a loss of control are accounted for as equity transactions, and the difference between the adjustment to the non-controlling When the accounting policies of the subsidiaries are different from those of the Group, the financial statements of subsidiaries are adjusted to ensure that the accounting policies are consistent with those of the Group. All intragroup balances, transaction amounts and unrealized gains and losses arising from intragroup transactions are eliminated in full in preparing the consolidated financial statements. Intragroup losses are eliminated in full except to the extent that the underlying asset is impaired. (b) Investments in associates An associate is an entity over which the Group has significant influence, which is the power to participate in the financial and operating policy decisions of the investee but there are no control. In principle, it is presumed that the Group has significant influence over an investee when the Group holds 20% or more but no more than 50% of the voting rights of the investee. An investee is determined as an associate when the Group has significant influence over it in one or more ways, not only the ratio of the voting rights, but also through participation in the policy-making progress and other right. An investment in an associate is accounted for under the equity method from the date when the Group has significant influence over it until the date when the significant influence is lost. Under the equity method, the investment is initially recognized at cost, and any excess of the Group’s share of the acquisition-date fair value of the investee’s identifiable net assets over the cost of the investment is recognized as goodwill that is included in the carrying amount of the investment. Thereafter, the investment is adjusted for the change in the Group’s share of the investee’s profit or loss and other comprehensive income. When the Group’s share of losses exceeds its interest in the associate, the Group’s interest is reduced to zero and recognition of further losses over the carrying amount of the investment is discontinued except to the extent that the Group assumes obligations or makes payments on behalf of the investee. When the Group ceases to have significant influence over an associate and discontinues the use of the equity method, gain or loss arising from discontinuance of the use of the equity method is recognized in profit or loss. Goodwill arising from the acquisition of an associate forms a part of the carrying amount of investments in the associate and is not separately recognized. Therefore, the goodwill of investment in an associate is not subject to impairment test separately. However, whenever there is any possibility that an investment in an associate may be impaired, the entire carrying amount of the investment is tested for impairment as a single asset. Regarding impairment of goodwill, refer to (10) “Impairment of non-financial (c) Joint arrangements The Group determines the type of a joint arrangement in which it is involved by considering its rights and obligations arising from the arrangement. When the parties that have joint control of an arrangement have rights to the assets, and obligations for the liabilities, relating to the arrangement, the arrangement is classified as a joint operation. When the parties that collectively control the arrangement have rights to the net assets of the arrangement and decisions about the relevant activities require the unanimous consent of those parties, that arrangement is classified as a joint venture. (d) Scope of consolidation and Application of equity method Number of consolidated subsidiaries: 420 companies At the end of fiscal year 2018, the scope of consolidation expanded by 46 companies, including 45 newly acquired companies and 1 newly established company. 19 companies, mainly 8 liquidations and 6 merged companies, were eliminated from the scope of consolidation during the fiscal year ended March 31, 2019. Number of equity-method affiliates (associates, jointly controlled businesses and jointly controlled companies) were 119 companies During the consolidated fiscal year 4 companies were added and 8 companies were removed from the scope of equity-method affiliates. (2) Business combinations Business combinations are accounted for using the acquisition method when control is obtained. The identifiable assets acquired and the liabilities assumed of the acquiree are recognized at fair value as of the acquisition date. When the total of consideration transferred in business combinations and amount of non-controlling non-controlling The consideration transferred for the acquisition is measured as the total of fair value of the assets transferred, the liabilities incurred to former owners of the acquiree and the equity interests issued by the acquirer. In addition, the fair value of equity interest in the acquiree that the Group held before the date of obtaining control is included in the consideration transferred for a business combination achieved in stages. Acquisition costs attributable to a business combination are recognized as expenses as incurred. Non-controlling non-controlling acquisition-by-acquisition The components of profit or loss and other comprehensive income are attributed to owners of the parent and non-controlling interests based on the proportionate shares held. (3) Foreign currency translation (a) Functional currency and presentation currency The financial statements of each Group entity are presented in its functional currency that is the currency of the primary economic environment in which the entity operates. The consolidated financial statements are presented in Japanese yen, which is the functional currency of the Company. (b) Foreign currency transactions Foreign currency transactions are translated into the functional currency using the spot exchange rate at the transaction date or using the foreign exchange rate that approximates such rate. Foreign currency monetary items at the end of each reporting period are translated into the functional currency using the exchange rate at the end of each reporting period. Non-monetary Non-monetary (c) Foreign operations The financial performance and financial position of all of foreign operations which use a functional currency other than the presentation currency are translated into the presentation currency of the Company using the following exchange rates: (i) Assets and liabilities are translated using the exchange rates at the reporting date (ii) Income and expenses are translated at average exchange rates (iii) All resulting exchange differences arising from translation of foreign operations are recognized in other comprehensive income. When a foreign operation is disposed of, the cumulative amount of the exchange differences recognized in other comprehensive income is reclassified to profit or loss. (4) Financial instruments (a) Non-derivative (i) Recognition and measurement The Group recognizes financial assets when it becomes a party to the contractual provisions of the assets. Financial assets purchased or sold in a regular way are recognized on the trade date. Financial assets other than derivative financial instruments are classified at initial recognition as those measured at amortized cost or at fair value through other comprehensive income. Financial assets measured at amortized cost and fair value through other comprehensive income are initially recognized at their fair value plus transaction costs that are directly attributable to the acquisition of the assets. Financial assets measured at amortized cost Financial assets are classified as financial assets measured at amortized cost only if the assets are held within the Group’s business model with an objective of collecting contractual cash flows, and if the contractual terms of the financial assets give rise on specified dates to cash flows that are solely payments of principal and interest on the principal amount outstanding. However, the trade receivables that do not contain a significant financing component are recognized initially at their transaction price. Financial assets measured at fair value through other comprehensive income For certain equity instruments held primarily for the purpose of maintaining or strengthening business relationship with investees, the Group designates these instruments as financial assets measured at fair value through other comprehensive income at initial recognition. Subsequent changes in fair value are recognized in other comprehensive income. When these financial assets are derecognized or significant deterioration of fair value occurs, a gain or loss accumulated in other comprehensive income is reclassified to retained earnings. Dividends from the financial assets measured at fair value through other comprehensive income are recognized in profit or loss when the Group’s right to receive dividends is established. (ii) Derecognition Financial assets are derecognized when the contractual rights to the cash flows from the financial assets expire, or when the Group transfers the financial assets and substantially all the risks and rewards of ownership of the assets to another party. (iii) Impairment of financial assets measured at amortized cost The Group assesses expected credit loss at the end of each reporting period for the impairment of financial assets measured at amortized cost. The loss allowance is measured at an amount equal to the lifetime expected credit losses for trade receivables and financial assets with a significant increase in credit risk since initial recognition. The Group determines whether credit risk has significantly increased based on changes in the risk of a default occurring on the financial assets. When determining whether there are changes in the risk of a default occurring on the financial assets, the Group considers the following; • Significant deterioration in the financial conditions of an issuer or a borrower; • A breach of contract, such as default or past-due • It has become probable that a borrower will enter into bankruptcy or other financial reorganization (b) Non-derivative (i) Recognition and measurement Financial liabilities other than derivatives are classified as financial liabilities measured at amortized cost. (ii) Derecognition The Group derecognizes financial liabilities when the obligation specified in the contract is discharged, cancelled or expires. (c) Offsetting of financial instruments Financial assets and financial liabilities are offset and the net amount is presented in the consolidated statement of financial position only when the Group currently has a legally enforceable right to offset the recognized amounts and intends either to settle on a net basis or to realize the assets and settle the liabilities simultaneously. (d) Derivatives and hedge accounting The Group utilizes derivatives, including foreign exchange forward contracts, interest rate swaps and currency swaps, to hedge foreign currency risk and interest rate risk. These derivatives are initially recognized at fair value when the contract is entered into, and are subsequently measured at fair value. Changes in fair value of derivatives are recognized in profit or loss. However, the effective portion of cash flow hedges is recognized in other comprehensive income. The Group formally documents relationships between hedging instruments and hedged items, as well as its risk management objective and strategies for undertaking various hedge transactions in an internal rule titled “Administrative Provisions on Transactions of Derivative Instruments”. The rule stipulates that derivative transactions are conducted only for the purpose of mitigating risks arising from the Group’s principal business activities (including forecast transactions) and the trading of derivatives for speculative purposes is prohibited. The Group evaluates whether the derivatives designated as a hedging instrument offsets changes in fair value or the cash flows of the hedged items to a great extent when designating a hedging relationship and on an ongoing basis. A hedging relationship that qualifies for hedge accounting is classified and accounted for as follows: (i) Fair value hedges Changes in fair value of derivative as a hedging instrument are recognized in profit or loss. Changes in fair value of a hedged item adjust the carrying amount of the hedged item and are recognized in profit or loss. (ii) Cash flow hedges The effective portion of changes in fair value of derivative as a hedging instrument is recognized in other comprehensive income. Any ineffective portion of changes in fair value of derivative as the hedging instrument is recognized in profit or loss. The amount accumulated in other comprehensive income is reclassified to profit or loss when the hedged transactions affect profit or loss. When a hedged item results in the recognition of a non-financial non-financial non-financial non-financial (5) Cash and cash equivalents Cash and cash equivalents comprises of cash on hand, bank deposits available for withdrawal on demand, and short-term investments with the maturity of three months or less from the acquisition date, that are readily convertible to cash and subject to an insignificant risk of changes in value. (6) Inventories Inventories are measured at the lower of cost or net realizable value. The cost of inventories is measured based on the weighted average method, and comprises of all costs of purchasing and processing as well as other costs incurred in bringing the inventories to their present location and condition. Net realizable value represents the estimated selling price in the ordinary course of business less the estimated costs of completion and the estimated costs necessary to make the sale. (7) Property, plant and equipment (a) Recognition and measurement Property, plant and equipment is initially measured at cost and presented at cost less accumulated depreciation and impairment losses. Acquisition cost includes costs directly attributable to the acquisition of the asset and costs of dismantling, removing and restoration of the asset. (b) Depreciation Depreciation of property, plant and equipment is mainly computed by the declining-balance method over the estimated useful lives of each component based on the depreciable amount, except for land and other non-depreciable The estimated useful lives of major property, plant and equipment are as follows: •  Buildings: Principally 31 years •  Machinery: Principally 14 years The depreciation methods, estimated useful lives and residual values are reviewed at the end of each reporting period, and modified as necessary. (8) Goodwill and intangible assets Intangible assets are measured at cost. Intangible assets with finite useful lives are presented at cost less accumulated amortization and impairment losses. Goodwill and intangible assets with indefinite useful lives are presented at cost less accumulated impairment losses. (a) Goodwill When the total of consideration transferred in business combinations and amount of non-controlling Goodwill is not amortized and is allocated to cash-generating units or groups of cash-generating units. Regarding accounting policy for impairment of goodwill, refer to (10) “Impairment of non-financial (b) Intangible assets Intangible assets acquired separately are measured at cost at the date of initial recognition. The costs of intangible assets acquired in business combinations are measured at fair value at the acquisition date. Intangible assets with finite useful lives are presented at cost less accumulated amortization and impairment losses. Expenditures related to internally generated intangible assets are recognized as expenses when incurred, unless development expenses meet the criteria for capitalization. (c) Amortization Amortization of intangible assets with finite useful lives is recognized as an expense by the straight-line method over their estimated useful lives from the date when the assets are available for their intended use. The amortization methods and useful lives are reviewed at the end of each reporting period, and modified as necessary. The estimated useful lives of major intangible assets with finite useful lives are as follows: •  Software: Principally 5 years •  Mining rights: Principally 25 years Intangible assets with indefinite useful lives and intangible assets not yet available for use are not amortized. (d) Expenditure on research and development activities Expenditure on research activities is recognized in profit or loss as incurred. Development expenditure is capitalized only if the expenditure can be measured reliably, the product or process is technically and commercially feasible, future economic benefits are probable and the Group intends to and has sufficient resources to complete the development and to use or sell the asset. Otherwise, it is recognized in profit or loss as incurred. (9) Leases The Group determines whether an arrangement is, or contains, a lease based on the substance of the arrangement as of the commencement date of the lease. For the substance of the arrangement, it makes an assessment of whether the fulfillment of the arrangement is dependent on the use of a specific asset or group of assets, and whether a right to use of the asset is transferred under the arrangement. A lease is classified as a finance lease, if all the risks and rewards of ownership of an asset are substantially transferred to the Group. Otherwise, a lease is classified as an operating lease. (a) Finance lease Lease assets and lease liabilities are initially recognized at the lower of fair value at the commencement of the lease or present value of the minimum lease payments. If it is reasonably certain that ownership will be transferred to a lessee by the end of the lease term, the leased asset is depreciated principally by the declining-balance method over the estimated useful life of the asset. Otherwise, the asset is depreciated over the shorter of the estimated useful life or the lease term. (b) Operating lease Lease payments under an operating lease are recognized in profit or loss on a straight-line basis over the relevant lease term. (10) Impairment of non-financial For the non-financial The recoverable amount of an asset or a cash-generating unit is the higher of its fair value less costs to sell and its value in use. When the recoverable amount of the individual asset cannot be estimated, the Group estimates the recoverable amount of the cash-generating unit or the group of cash-generating units to which the asset belongs. The value in use is calculated by discounting the estimated future cash flows to the present value, and a pre-tax The cash-generating unit or the group of cash-generating units to which goodwill is allocated is the lowest level monitored for internal management purposes, and is not larger than an operating segment. As corporate assets do not independently generate cash inflows, when there is an indication that a corporate asset may be impaired, an impairment test is performed based on the recoverable amount of the cash-generating unit or the group of cash-generating units to which such corporate asset belongs. If the recoverable amount of the asset or the cash-generating unit is less than the carrying amount, the carrying amount of the asset is reduced to its recoverable amount and an impairment loss is recognized. The impairment loss recognized with respect to the cash-generating unit is allocated first to reduce the carrying amount of any goodwill allocated to the cash-generating unit, and then to reduce other assets of the unit on a pro-rata An impairment loss is reversed if there are indications that an impairment loss recognized in prior periods for an asset other than goodwill may no longer exist or may have decreased and the recoverable amount of the asset is greater than its carrying amount. The amount to be reversed would not exceed its carrying amount that would have been determined had no impairment loss been recognized for the asset in prior years. An impairment loss recognized in goodwill is not reversed. (11) Employee benefits Employee benefits include short-term employee benefits, retirement benefits, and other long-term employee benefits. (a) Short-term employee benefits Short-term employee benefit obligations are measured on an undiscounted basis and are recognized as expenses when the related service is provided. A liability is recognized for the amount expected to be paid under short-term cash incentive plans if the Group has a present legal or constructive obligation to pay in exchange for services provided by the employees in the prior period, and such obligation can be reliably estimated. (b) Retirement benefits Retirement benefit plans comprise of defined benefit corporate pension plans, defined contribution plans, and lump-sum (i) Defined benefit corporate pension plans and lump-sum The net defined benefit liabilities or assets of defined benefit plans are recognized as the present value of defined benefit obligations less the fair value of any plan assets. The present value of defined benefit obligations is calculated annually by qualified actuaries using the projected unit credit method. The discount rates are based on the market yields of high quality corporate bonds at the end of each reporting period that have terms consistent with the discount period, which is established as the estimated term of the retirement benefit obligations through to the estimated dates for payments of future benefits. Remeasurements of defined benefit plans are recognized immediately in other comprehensive income when incurred, while past service costs are recognized in profit or loss. (ii) Defined contribution plans Contributions to defined contribution retirement plans are recognized as expenses in the period when the employees render the related services. (12) Equity (a) Ordinary shares Ordinary shares are classified as equity. Costs directly attributable to the issuance of ordinary shares (net of tax effects) are recognized as a deduction from equity. (b) Treasury stock When the Company acquires treasury stocks, the consideration paid, including any directly attributable costs (net of tax effects), is deducted from equity. In case of disposal of treasury stocks, the difference between the consideration received and the carrying amount of treasury stocks is recognized in equity. (13) Revenue The Group has adopted IFRS 15 “Revenue from Contracts with Customers” from the fiscal year ended March 31, 2019. Under IFRS 15, revenue is recognized based on the following five-steps. Step 1: Identify the contract with a customer Step 2: Identify the performance obligations in the contract Step 3: Determine the transaction price Step 4: Allocate the transaction price to the performance obligations in the contract Step 5: Recognize revenue when or as the Group satisfies a performance obligation Revenue generated from Steelmaking and Steel Fabrication segment and Chemicals and Materials segment consists primarily of revenue generated from sale of goods while revenue generated from Engineering and Construction segment and System Solutions segment primarily consists of services rendered under construction contracts. (a) Sale of goods The Group recognizes revenue from sale of goods when the customer obtains control of the goods and therefore a performance obligation is satisfied at a point in time whereby the Group no longer retains physical possession of goods upon shipment, the Group has the right to be paid from the customer, and when the legal title is transferred to the customer. With respect to revenue from rendering of service whose performance obligation is satisfied at a point in time, the Group recognizes revenue when the rendering of service is completed. Revenue is measured at the amount of consideration received or receivable less discounts and rebates. The consideration of the transaction is primarily collected within one year after the satisfaction of the performance obligation and it does not contain a significant financing component. (b) Construction contracts and built-to-order The Group recognizes revenue from construction contracts and built-to-order With respect to revenue from rendering of services whose performance obligation is satisfied over time, the Group recognizes revenue evenly throughout the duration of the service. The Group has adopted IFRS 15 “Revenue from Contracts with Customers” from the fiscal year ended March 31, 2019. In applying IFRS 15, the Group elected to apply the cumulative effect transition method where the cumulative effect of applying the Standard is recognized at the date of initial application. The adoption of the standard had no significant effect on each amount recognized in the consolidated financial statements. (14) Income taxes Income taxes comprise of current taxes and deferred taxes, and are recognized in profit or loss, except for the items which are recognized directly in equity or other comprehensive income. Current taxes are measured at the amounts expected to be paid or recovered from the taxation authorities using the tax rates that have been enacted or substantively enacted at the end of the reporting period. Deferred tax assets and deferred tax liabilities are recognized based on future tax consequences attributable to temporary differences between the carrying amounts of assets or liabilities for accounting purposes and the tax bases of the assets or liabilities, carryforward of unused tax losses and tax credits. Deferred tax assets are recognized to the extent that it is probable that taxable profit will be available against which the deductible temporary differences, unused tax losses and unused tax credits can be utilized. Deferred tax assets are reviewed at the end of each reporting period and recognized only to the extent that it is probable that the tax benefits can be realized. However, deferred tax assets are not recognized if the initial recognition of an asset or liability in a transaction that is not a business combination affects neither accounting profit nor taxable profit at the time of the transaction. Deferred tax assets arising from deductible temporary differences associated with investments in subsidiaries, associates and interests in joint arrangements are recognized only to the extent of the following circumstances: • The temporary difference will reverse in the foreseeable future; and • Taxable profit will be available against which the temporary difference can be utilized. Deferred tax liabilities are recognized for all taxable temporary differences, except for the following circumstances: • On the initial recognition of goodwill; • On the initial recognition of an asset or liability in a transaction that is not a business combination affects neither accounting profit nor taxable profit at the time of the transaction; • Taxable temporary differences associated with investments in subsidiaries to the extent that the parent company is able to control the timing of the reversal of the temporary difference and it is probable that the temporary difference will not reverse in the foreseeable future. Deferred tax assets and deferred tax liabilities are offset when there is a legally enforceable right to offset current tax assets against current tax liabilities and in either of the following circumstances: • Income taxes are levied by the same taxation authority on the same taxable entity; or • Different taxable entities intend either to settle current tax assets and current tax liabilities on a net basis, or to realize the current tax assets and settle the current tax liabilities simultaneously. (15) Earnings per share Basic earnings per share is calculated by dividing the profit for the reporting period attributable to owners of the Company by the weighted average number of common stock outstanding during the period in which the number of treasury stock is excluded.

Significant Accounting Estimate

Significant Accounting Estimates and Judgments	12 Months Ended
	Mar. 31, 2019
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Significant Accounting Estimates and Judgments	4. Significant Accounting Estimates and Judgments The preparation of consolidated financial statements in accordance with IFRS requires management to make judgments, estimates and assumptions that affect the adoption of accounting policies and the reported amounts of assets, liabilities, income and expenses. However, actual results could differ from these estimates. The estimates and their underlying assumptions are reviewed on an ongoing basis. The effects of changes in accounting estimates are recognized in the period in which the estimates are revised. Information about judgments that have been made in the process of applying the Group’s accounting policies and that have the most significant effects on the amounts recognized in the consolidated financial statements is included in the following notes: • Note 3 (1) “Basis of consolidation” and Note 15 “Interests in Subsidiaries, Associates and Others” • Note 3 (4) “Financial instruments” and Note 33 “Financial Instruments” Information about uncertainty of key estimates and assumptions that may have significant risks of causing material adjustments to the carrying amounts of assets and liabilities in the subsequent reporting year is included in the following notes: • Note 3 (10) “Impairment of non-financial Non-Financial • Note 3 (11) “Employee benefits” and Note 20 “Employee Benefits” • Note 3 (13) “Revenue” and Note 23 “Revenue” • Note 3 (14) “Income taxes” and Note 16 “Income Taxes” • Note 36 “Loan Guarantees”

New Accounting Standards and In

New Accounting Standards and Interpretations Not Yet Applied	12 Months Ended
	Mar. 31, 2019
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New Accounting Standards and Interpretations Not Yet Applied	5. New Accounting Standards and Interpretations Not Yet Applied New standards, interpretations, and amendments to standards and interpretations that have not yet been adopted in the preparation of the consolidated financial statements as of March 31, 2019, are as follows. IASB issued IFRS 16 “Leases” in January 2016. IFRS 16 replaces existing lease guidance including IAS 17 “Leases”, IFRIC 4 “Determining whether an Arrangement contains a Lease”, SIC-15 SIC-27 IFRS 16 changes the definition of a lease and provides a single on-balance right-of-use right-of-use IFRS 16 is effective for annual periods beginning on or after January 1, 2019. Accordingly, the Group applies this standard initially on April 1, 2019. This standard can be applied retrospectively to each prior reporting period presented (retrospective approach) or retrospectively with the cumulative effect of initially applying this standard recognized at the date of initial application (modified retrospective approach). The Group applies the modified retrospective approach. The Group also applies the practical expedient to grandfather the definition of a lease on transition and applies this standard to all the lease contracts entered into prior to April 1, 2019 as identified under IAS 17 “Leases” and IFRIC 4 “Determining whether an Arrangement contains a Lease”. The impact of applying this standard to total assets and total liabilities in the consolidated financial statements is 31,944 million yen.

Reclassifications

Reclassifications	12 Months Ended
	Mar. 31, 2019
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Reclassifications	6. Reclassifications Certain prior amounts have been reclassified to conform to the presentation as of and for the year ended March 31, 2019

Segment Information

Segment Information	12 Months Ended
	Mar. 31, 2019
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Segment Information	7. Segment Information (1) Description of reportable segments The Company engages in the Steelmaking and Steel Fabrication business and acts as the holding company of the Group. The Group has four operating segments determined mainly based on product and service, which are Steelmaking and Steel Fabrication, Engineering and Construction, Chemicals and Materials, and System Solutions. Each operating segment shares the management strategy of the Group, while conducting its business activities independently from and in parallel with other companies of the Group. The following summary describes the operations of each reportable segment: Reportable segments Principal businesses Steelmaking and Steel Fabrication Manufacturing and sales of steel products Engineering and Construction Manufacturing and sales of industrial machinery, equipment and steel structures, construction projects under contract, waste processing and recycling, and supplying electricity, gas, and heat Chemicals and Materials Manufacturing and sales of coal-based chemical products, petrochemicals, electronic materials, materials and components for semiconductors and electronic parts, carbon fiber and composite products, and products that utilize technologies for metal processing System Solutions Computer systems engineering and consulting services; IT-enabled The Group changed its segments from the year ended March 31, 2019. The Group integrated Chemicals segment and New Materials segment to form Chemicals and Materials segment upon the establishment of Nippon Steel Chemical & Material Co., Ltd. by a merger of Nippon Steel & Sumikin Chemical Co., Ltd. and Nippon Steel & Sumikin Materials Co., Ltd. in October 2018. The segment information for the year ended March 31, 2018 and March 31, 2017 has been reclassified to reflect the change of segments. (2) Basis of measurement of segment revenue, profit or loss, assets, liabilities, and other items Inter-segment revenue is based on transaction prices between third parties. Segment profit for the year ended March 31, 2019 is measured using business profit. Segment profit for the year ended March 31, 2018 and March 31, 2017 is measured using ordinary profit under Japanese GAAP, which is adjusted to business profit on the consolidated statement of profit or loss. (3) Information about segment revenue, segment profit, segment assets and liabilities and other items Year ended March 31, 2019 (Millions of Yen) Reportable segment Subtotal Adjustments Consolidated Steelmaking Engineering Chemicals System Revenue Revenue from external customers 5,408,633 321,346 243,014 204,952 6,177,947 — 6,177,947 Inter-segment revenue or transfers 45,902 35,360 4,052 62,550 147,867 (147,867 ) — Total 5,454,536 356,707 247,067 267,503 6,325,814 (147,867 ) 6,177,947 Segment profit 274,672 9,474 25,095 26,576 335,818 1,122 336,941 Other items Depreciation and amortization 398,702 2,605 6,644 4,872 412,825 (4,208 ) 408,616 Share of profit in investments accounted for using the equity method 76,337 801 1,339 (5 ) 78,473 7,938 86,411 Segment assets 7,404,841 289,083 194,622 231,994 8,120,542 (71,013 ) 8,049,528 Other items Investments accounted for using the equity method 672,853 6,313 23,629 309 703,105 90,041 793,146 Capital expenditure 431,775 3,021 8,855 2,542 446,194 (5,363 ) 440,830 Segment liabilities (Interest-bearing 2,365,587 5,937 7,075 2,631 2,381,231 (12,000 ) 2,369,231 Notes: 1. The adjustments of segment profit of 1,122 million yen include investment return of 8,237 million yen from the equity method associate Nippon Steel Kowa Real Estate Co., Ltd., and elimination of inter-segment revenue or transfers of (7,114) million yen. 2. The adjustments of segment liabilities include the elimination of the Steelmaking and Steel Fabrication segment’s borrowings from the System Solutions segment. Year ended March 31, 2018 (Millions of Yen) Reportable segment Subtotal Adjustments Total IFRS Consolidated Steelmaking Engineering Chemicals System Revenue Revenue from external customers 4,983,335 260,908 234,108 190,310 5,668,663 — 5,668,663 44,302 5,712,965 Inter-segment revenue or transfers 33,910 33,360 3,709 53,889 124,868 (124,868 ) — — — Total 5,017,245 294,268 237,817 244,200 5,793,531 (124,868 ) 5,668,663 44,302 5,712,965 Segment profit 245,708 9,110 17,399 23,292 295,510 2,030 297,541 (8,840 ) 288,700 Other items Finance income 4,983 180 38 146 5,348 (202 ) 5,146 2,498 7,644 Finance costs 20,080 44 172 11 20,309 (202 ) 20,106 4,477 24,584 Depreciation and amortization 330,393 2,489 7,329 4,646 344,859 (4,140 ) 340,719 25,845 366,565 Share of profit in investments accounted for using the equity method 116,408 378 148 (10 ) 116,925 5,750 122,675 (57,018 ) 65,657 Segment assets 7,003,681 247,696 184,988 223,601 7,659,967 (67,554 ) 7,592,413 163,721 7,756,134 Other items Investments accounted for using the equity method 950,887 4,393 24,843 17 980,142 83,614 1,063,757 (264,517 ) 799,239 Capital expenditure 390,623 6,301 8,497 7,638 413,061 (1,130 ) 411,930 11,497 423,428 Segment liabilities (Interest-bearing debt) 2,057,997 8,313 11,519 3,693 2,081,524 (12,527 ) 2,068,996 88,759 2,157,755 Notes: 1. The adjustments of segment profit of 2,030 million yen include investment return of 5,929 million yen from the equity method associate Nippon Steel Kowa Real Estate Co., Ltd., and elimination of inter-segment revenue or transfers of (3,899) million yen. 2. The adjustments of segment liabilities include the elimination of the Steelmaking and Steel Fabrication segment’s borrowings from the System Solutions segment. Year ended March 31, 2017 (Millions of Yen) Reportable segment Subtotal Adjustments Total IFRS Consolidated Steelmaking Engineering Chemicals System Revenue Revenue from external customers 4,016,670 234,861 203,115 178,242 4,632,890 — 4,632,890 63,937 4,696,828 Inter-segment 35,590 32,683 5,630 54,270 128,175 (128,175 ) — — — Total 4,052,261 267,545 208,746 232,512 4,761,065 (128,175 ) 4,632,890 63,937 4,696,828 Segment profit 138,017 6,838 6,304 22,113 173,274 1,256 174,531 (4,652 ) 169,878 Other items Finance income 5,566 124 36 133 5,860 (206 ) 5,654 668 6,322 Finance costs 17,831 118 233 28 18,212 (206 ) 18,006 3,579 21,586 Depreciation and amortization 294,008 2,653 8,227 4,174 309,064 (4,313 ) 304,751 26,161 330,912 Share of profit in investments accounted for using the equity method 70,723 655 920 21 72,320 6,859 79,180 (35,062 ) 44,118 Other items Capital expenditure 335,733 5,637 9,229 4,343 354,943 (3,905 ) 351,038 11,486 362,525 Notes: 1. The adjustments of segment profit of 1,256 million yen include investment return of 6,524 million yen from the equity method associate Nippon Steel Kowa Real Estate Co., Ltd., investment return of 629 million yen from the equity method associate SUMCO Corporation, and elimination of inter-segment revenue or transfers of (5,897) million yen. 2. The adjustments of segment liabilities include the elimination of the Steelmaking and Steel Fabrication segment’s borrowings from the System Solutions segment. (4) Information about geographical areas (a) Revenue Year ended March 31, 2019 (Millions of Yen) Japan Overseas Asia Other Total 4,053,188 2,124,758 1,310,890 813,868 6,177,947 Year ended March 31, 2018 (Millions of Yen) Japan Overseas Asia Other Total 3,729,176 1,983,789 1,274,380 709,409 5,712,965 Year ended March 31, 2017 (Millions of Yen) Japan Overseas Asia Other Total 2,980,400 1,716,427 1,068,459 647,967 4,696,828 Revenue information is based on the geographical location of customers and classified by region. (b) Non-current assets As of March 31, 2019 (Millions of Yen) Japan Overseas Total 2,978,818 435,078 3,413,896 As of March 31, 2018 (Millions of Yen) Japan Overseas Total 2,854,097 418,238 3,272,335 Non-current assets are based on the location of the asset and do not include financial assets, deferred tax assets and assets for retirement benefits. (5) Revenue from major customers (Millions of Yen) Related segment Year ended Year ended Year ended Nippon Steel & Sumikin Bussan Corporation Steelmaking and Steel Fabrication 1,170,241 849,244 744,657 Sumitomo Corporation Steelmaking and Steel Fabrication 762,888 772,942 674,139 Metal One Corporation Steelmaking and Steel Fabrication 631,639 592,146 —

Business Combinations

Business Combinations	12 Months Ended
	Mar. 31, 2019
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Business Combinations	8. Business Combinations Business combinations during the years ended March 31, 2017, 2018 and 2019 are as follows: (1) Business combinations consummated during the year ended March 31, 2019 Ovako AB (a) Overview On June 1, 2018, the Company acquired all outstanding shares of Ovako AB (“Ovako”), which is headquartered in Sweden and is primarily engaged in the manufacturing and sale of special steel products and secondarily processed products mainly in Europe, for cash consideration of 51,767 million yen. With this acquisition, the Company seeks to strengthen the position of the Group as “The Best Steelmaker with World-Leading Capabilities”, thereby aiming to achieve sustainable growth and enhance the Group’s corporate value in the mid-to long-term. With the addition of Ovako, the Group will bring together Ovako’s high-cleanliness steel for bearing steel and other related products to the Company’s product portfolio to strengthen and expand its global special steel business. (b) Consideration transferred (Millions of Yen) Cash 51,767 Total consideration transferred 51,767 The Group incurred acquisition-related costs of ¥1,215 million yen as selling, general and administrative expenses in the consolidated statements of profit and loss. (c) Fair value of the assets acquired and liabilities assumed and goodwill (Millions of Yen) Current assets 63,555 Non-current assets 53,302 Total assets 116,858 Current liabilities 70,691 Non-current liabilities 17,032 Total liabilities 87,724 Total identifiable net assets acquired 29,133 Total equity attributable to owners of the parent 29,133 Total consideration transferred 51,767 Goodwill 22,634 The goodwill is attributable mainly to an excess earning power expected to be achieved from the synergies between the Group and the Ovako. The goodwill is not tax-deductible. (d) Net cash used in the transaction (Millions of Yen) Cash consideration transferred 51,767 Cash and cash equivalents held by the acquiree at the acquisition date (5,961 ) Net cash used in the transaction 45,805 (e) Revenue and profit or loss of the Ovako after the acquisition date Information about revenue and profit or loss generated subsequent to the acquisition date through March 31, 2019 is not disclosed as it is immaterial to the consolidated financial statements. (f) Revenue and profit or loss of the Group if the business combination had been completed at the beginning of the year Information about revenue and profit or loss of the Groups if business combination had been completed at the beginning of the year is not disclosed as it is immaterial to the consolidated financial statements. Sanyo Special Steel Co., Ltd. (a) Overview On March 28, 2019, the Company acquired 36.2% equity interest of Sanyo Special Steel Co., Ltd. (“Sanyo”), which is primarily engaged in the manufacturing and sale of special steel products, powders and formed and fabricated materials through purchase of newly issued shares. As a result of the acquisition, the equity interests held by the Company increased from 15.3% to 51.5% and Sanyo became a subsidiary of the Company. The acquisition of Sanyo and Ovako allows the Company to strengthen its medium-to long-term competitiveness of the special steel businesses by bringing together our business foundations, technical and product development capabilities and cost competitiveness of the three companies to respond to globalization of the customers in the automobile and other fields as well as customer needs for high-quality special steel products. (b) Consideration transferred (Millions of Yen) Cash 67,235 Fair value of equity interests held before the acquisition date 13,737 Total consideration transferred 80,972 The Company recorded a loss of 4,592 million yen as other operating expenses in the consolidated statements of profit or loss as a result from fair value measurement conducted at the acquisition date of the equity interests in Sanyo held prior to the acquisition date. The Group recorded acquisition-related costs of ¥276 million yen as selling, general and administrative expenses in the consolidated statements of profit and loss. (c) Fair value of the assets acquired and liabilities assumed, non-controlling interests and bargain purchase gain The Company has not completed the fair value measurement of acquired assets and assumed liabilities, and accordingly the computation of non-controlling interests, bargain purchase gain and the purchase price allocations are on a provisional basis based on the most current information available. (Millions of Yen) Current assets 210,344 Non-current assets 75,075 Total assets 285,419 Current liabilities 61,789 Non-current liabilities 38,804 Total liabilities 100,593 Total identifiable net assets acquired 184,826 Non-controlling interests 90,274 Total equity attributable to owners of the parent 94,551 Total consideration transferred 80,972 Bargain purchase gain 13,578 Non-controlling interests are measured at the proportionate share of the fair value of the Sanyo’s identifiable total equity. The Group recorded the difference between total equity attributable to the owners of the parent and total consideration transferred in the amount of 13,578 million yen as “Other operating income” in the consolidated statements of profit or loss for the year ended March 31, 2019. (d) Net cash used in the transaction (Millions of Yen) Cash consideration transferred 67,235 Cash and cash equivalents held by the Sanyo at the acquisition date (79,196 ) Net cash provided in the transaction (11,961 ) Cash and cash equivalents held by Sanyo at the acquisition date include the proceeds from equity financing in the amount of 67,235 million yen. (e) Revenue and profit or loss of the Sanyo after the acquisition date Information about revenue and profit or loss generated subsequent to the acquisition date through March 31, 2019 is not disclosed as it is immaterial to the consolidated financial statements. (f) Revenue and profit or loss of the Group if the business combination had been completed at the beginning of the year (Unaudited) (Millions of Yen) Revenue 6,363,765 Profit before income taxes 259,145 (2) Business combinations consummated during the year ended March 31, 2018 No business combinations occurred during the year ended March 31, 2018. (3) Business combinations consummated during the year ended March 31, 2017 (a) Overview On March 13, 2017, the Company acquired 43% equity interest of Nisshin Steel Co., Ltd. (“Nisshin Steel”), which is primarily engaged in the steelmaking and steel fabrication business, for cash consideration. As a result of the acquisition, the equity interests held by the Company increased from 8% to 51% and Nisshin Steel became a subsidiary of the Company. The acquisition was consummated in order for the Company and Nisshin Steel to bring together the respective management resources that they have fostered and create synergies, and thereby enhance competitiveness, and to strengthen the position of the Group as the “Best Steelmaker with World-Leading Capabilities”. With the addition of Nisshin Steel, the Company aims to enhance sustainable growth and corporate value in the mid-to long-term and contribute to the creation and development of a more prosperous society. (b) Consideration transferred (Millions of Yen) Cash 75,972 Fair value of equity interests held before the date of acquisition 14,781 Total consideration transferred 90,753 The Group incurred acquisition-related costs of 627 million yen. (c) Fair value of the assets acquired and liabilities assumed, non-controlling interests and goodwill (Millions of Yen) Current asset 246,040 Non-current assets 423,937 Total assets 669,978 Current liabilities 224,318 Non-current liabilities 259,936 Total liabilities 484,255 Total identifiable net assets acquired 185,722 Non-controlling interests 98,105 Total equity attributable to owners of the parent 87,616 Total consideration transferred 90,753 Goodwill 3,136 Non-controlling interests are measured at the proportionate share of the fair value of the acquiree’s identifiable net assets. The goodwill is attributable mainly to an excess earning power expected to be achieved from the synergies between the Group and the acquiree. The goodwill is not tax-deductible. (d) Net cash used in the transaction (Millions of Yen) Cash consideration transferred 75,972 Cash and cash equivalents held by the Nisshin Steel at the acquisition date (23,079 ) Net cash used in the transaction 52,892 (e) Revenue and net profit or loss of the Nisshin Steel after the acquisition date Information about profit or loss generated subsequent to the acquisition date through March 31, 2018 is not disclosed as it is immaterial to the consolidated financial statements. (f) Revenue and profit or loss of the Group if the business combination had been completed at the beginning of the year (Unaudited) (Millions of Yen) Revenue 5,222,392 Profit before income taxes 199,831

Cash and Cash Equivalents

Cash and Cash Equivalents	12 Months Ended
	Mar. 31, 2019
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Cash and Cash Equivalents	9. Cash and Cash Equivalents The components of cash and cash equivalents are as follows: (Millions of Yen) As of As of As of Cash 159,636 138,702 119,793 Cash equivalents 3,540 4,166 4,135 Total 163,176 142,869 123,929

Trade and Other Receivables

Trade and Other Receivables	12 Months Ended
	Mar. 31, 2019
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Trade and Other Receivables	10. Trade and Other Receivables The components of trade and other receivables are as follows: (Millions of Yen) As of As of Notes and accounts receivable 842,573 730,805 Other 128,166 103,336 Allowance for doubtful receivables (2,407 ) (2,101 ) Total 968,333 832,040 Contract assets are included in “Notes and accounts receivables”.

Inventories

Inventories	12 Months Ended
	Mar. 31, 2019
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Inventories	11. Inventories The components of inventories are as follows: (Millions of Yen) As of As of Merchandise and finished goods 831,597 701,173 Work in progress 87,814 72,425 Raw materials and supplies 647,704 626,222 Total 1,567,116 1,399,821

Assets Pledged as Collateral

Assets Pledged as Collateral	12 Months Ended
	Mar. 31, 2019
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Assets Pledged as Collateral	12. Assets Pledged as Collateral As per general contractual provisions for long-term and short-term borrowings, banks may require collateral and guarantees for present and future obligations, and retain the rights to offset the liabilities with bank deposits when repayment is overdue or when default occurs. Assets pledged as collateral and secured debts are as follows: (Millions of Yen) Assets pledged as collateral As of As of Land 11,432 10,855 Buildings and structures 4,853 3,784 Machinery and vehicles 5,471 6,826 Other 13,475 4,907 Total 35,233 26,373 (Millions of Yen) Secured debts As of As of Short-term borrowings 3,635 970 Long-term borrowings (current portion is included) 6,242 5,383 Other 467 447 Total 10,345 6,801 In addition to the pledged assets listed above, shares of associates are pledged as collateral (1,301 million yen, and 1,261 million yen as of March 31, 2019 and 2018, respectively).

Property, Plant and Equipment

Property, Plant and Equipment	12 Months Ended
	Mar. 31, 2019
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Property, Plant and Equipment	13. Property, Plant and Equipment Details of changes in the carrying amounts and acquisition costs, accumulated depreciation and accumulated impairment losses of property, plant and equipment are as follows: (Millions of Yen) Carrying amount Land Buildings Machinery Tools, Leased Construction Total As of March 31, 2017 654,349 815,580 1,266,968 48,413 46,783 260,106 3,092,202 Acquisitions and reclassified from construction in progress 1,831 71,336 277,566 24,810 10,401 16,255 402,200 Disposals and sales (2,858 ) (4,081 ) (2,637 ) (621 ) (246 ) (803 ) (11,249 ) Depreciation — (58,469 ) (257,642 ) (19,000 ) (9,486 ) — (344,599 ) Impairment losses (536 ) (5,955 ) (8,344 ) (564 ) — — (15,401 ) Effects of changes in foreign exchange rates (421 ) 868 10,997 189 (627 ) (10,300 ) 705 As of March 31, 2018 652,364 819,277 1,286,908 53,226 46,823 265,258 3,123,857 Acquisitions and reclassified from construction in progress 5,967 78,086 363,975 85,546 7,812 (72,830 ) 468,557 Acquisitions through business combinations 9,653 20,579 56,261 1,082 — 6,755 94,331 Disposals and sales (5,258 ) (3,660 ) (6,037 ) (4,570 ) (131 ) (129 ) (19,788 ) Depreciation — (58,817 ) (272,371 ) (46,659 ) (9,498 ) — (387,347 ) Effects of changes in foreign exchange rates (1,224 ) (190 ) (25,447 ) 719 (38 ) (6,758 ) (32,941 ) As of March 31, 2019 661,502 855,274 1,403,287 89,343 44,967 192,294 3,246,669 Depreciation of property, plant and equipment is mainly included in “Cost of sales” and “Selling, general and administrative expenses” in the consolidated statements of profit or loss. (Millions of Yen) Acquisition costs Land Buildings Machinery Tools, Leased Construction Total As of March 31, 2017 705,539 2,555,698 7,998,199 317,753 277,165 308,196 12,162,552 As of March 31, 2018 701,984 2,607,700 8,215,605 327,419 276,851 313,262 12,442,823 As of March 31, 2019 710,235 2,730,502 8,733,560 407,619 280,382 196,767 13,059,068 (Millions of Yen) Accumulated depreciation and Land Buildings Machinery Tools, Leased Construction Total As of March 31, 2017 51,189 1,740,118 6,731,230 269,340 230,382 48,089 9,070,350 As of March 31, 2018 49,620 1,788,422 6,928,697 274,193 230,027 48,003 9,318,966 As of March 31, 2019 48,733 1,875,228 7,330,272 318,276 235,414 4,473 9,812,398 The carrying amounts by type of leased assets are as follows: (Millions of Yen) Buildings and Machinery and Tools, furniture Total As of March 31, 2017 11,895 31,994 2,893 46,783 As of March 31, 2018 10,748 32,005 4,069 46,823 As of March 31, 2019 10,024 31,701 3,241 44,967

Goodwill and Intangible Assets

Goodwill and Intangible Assets	12 Months Ended
	Mar. 31, 2019
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Goodwill and Intangible Assets	14. Goodwill and Intangible Assets Details of changes in the carrying amounts and acquisition costs, accumulated amortization and accumulated impairment losses of goodwill and intangible assets are as follows: (Millions of Yen) Carrying amount Goodwill Software Mining rights Other Total As of March 31, 2017 44,563 47,165 44,630 5,878 142,237 Acquisitions — 18,698 — 2,528 21,227 Amortization — (18,443 ) (2,306 ) (1,215 ) (21,965 ) Impairment losses (2,472 ) (139 ) — (61 ) (2,673 ) Effects of changes in foreign exchange rates 173 (1,066 ) 1,898 (434 ) 569 As of March 31, 2018 42,263 46,214 44,221 6,695 139,395 Acquisitions — 19,470 — 807 20,278 Acquisitions through business combinations 22,634 1,891 — 16,333 40,859 Amortization — (17,868 ) (2,198 ) (1,202 ) (21,268 ) Impairment losses (10,963 ) — — — (10,963 ) Effect of changes in foreign exchange rates (1,131 ) (3,079 ) (4,884 ) (272 ) (9,367 ) As of March 31, 2019 52,803 46,629 37,139 22,362 158,934 Amortization of intangible assets is included in “Cost of sales” and “Selling, general and administrative expenses” in the consolidated statements of profit or loss. (Millions of Yen) Acquisition costs Goodwill Software Mining rights Other Total As of March 31, 2017 44,563 87,236 63,304 12,131 207,236 As of March 31, 2018 44,736 97,253 66,107 17,203 225,301 As of March 31, 2019 66,238 115,358 58,617 30,875 271,090 Accumulated amortization and (Millions of Yen) Goodwill Software Mining rights Other Total As of March 31, 2017 — 40,071 18,674 6,252 64,999 As of March 31, 2018 2,472 51,039 21,885 10,507 85,905 As of March 31, 2019 13,435 68,729 21,478 8,512 112,155

Interests in Subsidiaries, Asso

Interests in Subsidiaries, Associates and Others	12 Months Ended
	Mar. 31, 2019
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Interests in Subsidiaries, Associates and Others	15. Interests in Subsidiaries, Associates and Others (1) Major subsidiaries Major subsidiaries of the Company as of March 31, 2019 are as follows: Operating segment Name Address % of voting Steelmaking and Steel Fabrication Sanyo Special Steel Co., Ltd. Himeji-shi, Hyogo 51.5 % Steelmaking and Steel Fabrication Nisshin Co., Ltd. Chiyoda-ku, Tokyo 100.0 % Steelmaking and Steel Fabrication Nippon Steel & Sumikin Coated Sheet Corporation Chuo-ku, Tokyo 100.0 % Steelmaking and Steel Fabrication Osaka Steel Co., Ltd. Osaka-shi, Osaka 66.3 % Steelmaking and Steel Fabrication Nippon Steel & Sumikin Metal Products Co., Ltd. Koto-ku, Tokyo 100.0 % Steelmaking and Steel Fabrication Nippon Steel & Sumikin Pipe Co., Ltd. Chiyoda-ku, Tokyo 100.0 % Steelmaking and Steel Fabrication Kurosaki Harima Corporation Kitakyushu-shi, Fukuoka *47.0 % Steelmaking and Steel Fabrication Nippon Steel & Sumikin Texeng Co., Ltd. Chiyoda-ku, Tokyo 100.0 % Steelmaking and Steel Fabrication Nippon Steel & Sumikin Stainless Steel Corporation Chiyoda-ku, Tokyo 100.0 % Steelmaking and Steel Fabrication Nippon Steel & Sumikin Logistics Co., Ltd. Chuo-ku, Tokyo 100.0 % Steelmaking and Steel Fabrication Nippon Steel & Sumikin SG Wire Co., Ltd. Chiyoda-ku, Tokyo 100.0 % Steelmaking and Steel Fabrication Geostr Corporation Bunkyo-ku, Tokyo *42.3 % Steelmaking and Steel Fabrication Nippon Steel & Sumikin Welding Co., Ltd. Koto-ku, Tokyo 100.0 % Steelmaking and Steel Fabrication Nippon Steel & Sumikin Drum Co., Ltd. Koto-ku, Tokyo 100.0 % Steelmaking and Steel Fabrication Nippon Steel & Sumikin Blast Furnace Slag Cement Co., Ltd. Kitakyushu-shi, Fukuoka 100.0 % Steelmaking and Steel Fabrication Nippon Steel & Sumikin Cement Co., Ltd. Muroran-shi, Hokkaido 85.0 % Steelmaking and Steel Fabrication Nippon Steel & Sumikin Finance Co., Ltd. Chiyoda-ku, Tokyo 100.0 % Steelmaking and Steel Fabrication Nippon Steel & Sumikin Stainless Steel Pipe Co., Ltd. Koga-shi, Ibaraki 100.0 % Steelmaking and Steel Fabrication Nippon Steel & Sumikin Steel Wire Co., Ltd. Seki-shi, Gifu 51.0 % Steelmaking and Steel Fabrication Nippon Steel & Sumikin Eco-Tech Corporation Chuo-ku, Tokyo 85.1 % Steelmaking and Steel Fabrication Nippon Steel & Sumikin Bolten Corporation Osaka-shi, Osaka 85.0 % Steelmaking and Steel Fabrication Nippon Steel & SumikinShapes Corporation Wakayama-shi, Wakayama 100.0 % Steelmaking and Steel Fabrication Nippon Steel & Sumikin Tubos do Brasil Ltda. State of Rio de Janeiro, Brazil 100.0 % Steelmaking and Steel Fabrication NS-Siam United Steel Co., Ltd. Rayong Province, Thailand 80.2 % Steelmaking and Steel Fabrication National Pipe Company Limited Eastern Province, Saudi Arabia 51.0 % Steelmaking and Steel Fabrication Standard Steel, LLC Pennsylvania State, United States of America 100.0 % Steelmaking and Steel Fabrication Nippon Steel & Sumitomo Metal U.S.A., Inc. New York State, United States of America 100.0 % Steelmaking and Steel Fabrication PT Pelat Timah Nusantara Tbk. Jakarta City, Indonesia *35.0 % Steelmaking and Steel Fabrication Nippon Steel & Sumitomo Metal (Thailand) Co., Ltd. Bangkok Metropolis, Thailand 100.0 % Steelmaking and Steel Fabrication Nippon Steel & Sumitomo Metal Australia Pty. Limited New South Wales State, Australia 100.0 % Steelmaking and Steel Fabrication Nippon Steel & Sumikin Steel Processing (Thailand) Co., Ltd. Rayong Province, Thailand 66.5 % Steelmaking and Steel Fabrication Ovako AB Stockholm, Sweden 100.0 % Engineering and Construction Nippon Steel & Sumikin Engineering Co., Ltd. Shinagawa-ku, Tokyo 100.0 % Chemicals & Materials Nippon Steel Chemical & Material Co., Ltd. Chiyoda-ku, Tokyo 100.0 % System Solutions NS Solutions Corporation Chuo-ku, Tokyo 63.4 % * Although the Group holds less than 50% of the voting rights of Geostr Corporation, PT Pelat Timah Nusantara Tbk. and Kurosaki Harima Corporation, it includes the entities in consolidated subsidiaries because it substantially controls the entities. (2) Investments in associates Carrying amount of investments in associates is as follows: (Millions of Yen) As of As of Carrying amount of investments in associates 636,216 654,214 Share of net profit or loss and other comprehensive income of associates is as follows: (Millions of Yen) Year Ended Year Ended Year Ended Net profit or loss 49,436 38,199 29,622 Other comprehensive income (18,610 ) (270 ) 11,379 Total 30,826 37,929 41,002 (3) Investments in joint ventures Carrying amount of investments in joint ventures is as follows: (Millions of Yen) As of As of Carrying amount of investments in joint ventures 156,930 145,025 Share of net profit or loss and other comprehensive income of joint ventures is as follows: (Millions of Yen) Year Ended Year Ended Year Ended Net profit or loss 36,975 27,458 14,495 Other comprehensive income (6,030 ) 2,793 (1,108 ) Total 30,944 30,251 13,386 There are no investments in associates or joint ventures accounted for under the equity method that are individually significant to the Group for the years ended March 31, 2017, 2018 and 2019.

Income Taxes

Income Taxes	12 Months Ended
	Mar. 31, 2019
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Income Taxes	16. Income Taxes (1) Deferred tax assets and deferred tax liabilities (a) The components of deferred tax assets and deferred tax liabilities are as follows: (Millions of Yen) As of As of Deferred tax assets Accrued bonus 28,189 26,453 Defined benefit liabilities 66,924 48,011 Impairment losses on non-financial assets 17,888 11,637 Property, plant and equipment 21,552 19,482 Unused tax losses 39,280 29,330 Elimination of unrealized gains on property, plant and equipment and others 31,553 29,681 Accrued expenses for demolition and removal of fixed assets 15,024 13,807 Other 48,820 39,367 Total deferred tax assets 269,234 217,772 Deferred tax liabilities Equity securities (108,609 ) (151,451 ) Defined benefit assets (25,167 ) (33,357 ) Undistributed earnings (31,570 ) (30,904 ) Special tax purpose reserves (43,782 ) (62,466 ) Total deferred tax liabilities (209,130 ) (278,179 ) Net deferred tax assets (liabilities) 60,104 (60,407 ) (b) The changes in net deferred tax assets and liabilities are as follows: (Millions of Yen) Year Ended Year Ended Balance at beginning of the year (60,407 ) (38,993 ) Recognized in profit or loss 88,108 19,575 Recognized in other comprehensive income 37,761 (41,003 ) Effect of changes in consolidation scope (5,268 ) 14 Balance at end of the year 60,104 (60,407 ) (c) Deductible temporary differences and unused tax losses for which no deferred tax assets are recognized are as follows: (Millions of Yen) As of As of Carryforward of unused tax losses 51,390 87,225 Deductible temporary differences 111,242 131,854 Total 162,633 219,080 (d) The components by expiry date of unused tax losses for which no deferred tax assets are recognized are as follows: (Millions of Yen) As of As of Within 1 year 3,009 30,935 Over 2 years but less than 3 years 5,209 7,774 Over 3 years but less than 4 years 10,640 11,426 Over 4 years but less than 5 years 1,247 17,003 Over 5 years 31,283 20,085 Total 51,390 87,225 (2) Income tax expense (a) Details of income tax expense are as follows: (Millions of Yen) Year Ended Year Ended Year Ended Current taxes 79,209 79,124 49,526 Deferred taxes (88,018 ) (19,575 ) (9,229 ) Total (8,809 ) 59,549 40,297 The Tax Cut and Jobs Act was enacted on December 22, 2017 and the federal corporate income tax rate applicable to the Company’s subsidiaries in the US was reduced from 35% to 21%. As a result of the reduction, deferred tax for the year ended March 31, 2018 decreased by 6,253 million yen. (b) Differences between the statutory income tax rate and the Group’s average effective tax rate consist of the following: Year Ended Year Ended Year Ended Statutory tax rate 30.6 % 30.9 % 30.9 % Share of profit in investments accounted for using the equity method (7.3 ) (4.8 ) (4.5 ) Effects of expense not deductible for tax purposes 0.9 0.9 1.1 Effects of income not taxable for tax purposes (0.6 ) (0.6 ) (1.0 ) Effects of differences in statutory tax rates applied to companies in Japan and foreign companies (1.8 ) (2.3 ) (2.0 ) Effects of changes in unrecognized deferred tax assets (24.0 ) (4.0 ) (8.1 ) Other (1.4 ) 1.9 4.3 Average effective tax rate (3.5 ) 21.9 20.7

Trade and Other Payables

Trade and Other Payables	12 Months Ended
	Mar. 31, 2019
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Trade and Other Payables	17. Trade and Other Payables The components of trade and other payables are as follows: (Millions of Yen) As of As of Notes and trade accounts payable 821,009 782,605 Other payables 524,167 474,903 Other 266,226 323,087 Total 1,611,403 1,580,597

Bonds, Borrowings and Lease Lia

Bonds, Borrowings and Lease Liabilities	12 Months Ended
	Mar. 31, 2019
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Bonds, Borrowings and Lease Liabilities	18. Bonds, Borrowings and Lease Liabilities (1) Bonds, borrowings and lease liabilities Details of bonds, borrowings and lease liabilities are as follows: (Millions of Yen) As of Average As of Average Maturity date Short-term borrowings 215,393 1.2 137,323 1.0 — Current portion of long-term borrowings repayable within one year 111,177 1.0 184,809 1.0 — Current portion of bonds repayable within one year 60,000 1.4 85,700 1.5 — Current portion of lease liabilities repayable within one year 8,783 0.8 8,550 0.8 — Commercial papers 120,000 (0.0 ) 89,000 (0.0 ) — Long-term borrowings 1,595,905 0.8 1,401,156 0.8 July 19, 2075 Bonds 220,000 0.7 209,996 1.0 September 19, 2031 Lease liabilities 37,970 0.8 41,218 0.8 March 31, 2076 Total 2,369,231 2,157,755 “Average interest rate” represents the weighted average interest rate to the aggregate balance at the end of the reporting period. (2) Details of bonds (Millions of Yen) Type Issue date As of As of Maturity date Bonds issued by NSC Japanese Yen Corporate Bonds Maturity 2019 February 15, 1999 — 696 February 15, 2019 The 58 th September 2, 2008 — 30,000 June 20, 2018 The 59 th September 2, 2008 10,000 10,000 June 20, 2028 The 61 st December 2, 2008 — 15,000 September 20, 2018 The 63 rd June 9, 2009 20,000 20,000 June 20, 2019 The 64 th April 20, 2010 20,000 20,000 March 19, 2020 The 65 th August 31, 2010 15,000 15,000 June 19, 2020 The 67 th May 24, 2011 30,000 30,000 March 19, 2021 The 65 th May 31, 2011 — 10,000 May 31, 2018 The 68 th October 20, 2011 15,000 15,000 September 17, 2021 The 68 th October 20, 2011 — 10,000 October 19, 2018 The 70 th April 20, 2012 10,000 10,000 April 19, 2019 The 69 th July 20, 2012 10,000 10,000 June 20, 2019 The 70 th July 20, 2012 20,000 20,000 June 20, 2022 The 1 st September 26, 2016 10,000 10,000 September 18, 2026 The 2 nd September 26, 2016 10,000 10,000 September 19, 2031 The 3 rd May 25, 2017 10,000 10,000 May 20, 2024 The 4 th May 25, 2017 10,000 10,000 May 20, 2027 The 5 th December 8, 2017 10,000 10,000 December 20, 2024 The 6 th December 8, 2017 10,000 10,000 December 20, 2027 The 7 th June 12, 2018 20,000 — June 20, 2023 The 8 th June 12, 2018 20,000 — June 20, 2025 The 9 th June 12, 2018 20,000 — June 20, 2028 Bonds issued by Nisshin Steel The 19 th June 2, 2008 — 10,000 June 1, 2018 The 23 rd March 10, 2014 — 10,000 March 8, 2019 Bonds issued by Sanyo Special Steel The 2nd Issue of Unsecured Corporate Bonds December 7, 2017 10,000 — December 6, 2024 Total 280,000 295,696 (3) Reconciliation of changes in liabilities in cash flows from financing activities The table below presents a reconciliation of main changes in liabilities arising from financing activities. (Millions of Yen) Short-term Commercial Long-term Bonds Lease Total As of March 31, 2017 142,769 31,854 1,595,610 396,005 48,688 2,214,928 Cash flows from financing activities (7,114 ) 57,140 2,672 (100,000 ) (12,377 ) (59,677 ) Effects of changes in consolidation scope 1,331 — 1,435 — (7 ) 2,759 Effects of changes in foreign exchange rates 276 4 (10,865 ) — 196 (10,387 ) Other 60 — (2,886 ) (309 ) 13,267 10,132 As of March 31, 2018 137,323 89,000 1,585,966 295,696 49,768 2,157,755 Cash flows from financing activities 44,401 23,000 102,850 (25,700 ) (9,792 ) 134,760 Effects of changes in consolidation scope 35,073 8,000 20,872 10,000 (65 ) 73,880 Effects of changes in foreign exchange rates (1,220 ) — (2,013 ) — (43 ) (3,277 ) Other (184 ) — (593 ) 3 6,886 6,112 As of March 31, 2019 215,393 120,000 1,707,083 280,000 46,754 2,369,231

Leases

Leases	12 Months Ended
	Mar. 31, 2019
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Leases	19. Leases The Group leases assets such as machinery as a lessee and land and buildings as a lessor. (1) Finance leases As a lessee Future minimum lease payments under finance lease contracts are as follows: (Millions of Yen) Year ended Year ended Within 1year 8,783 8,550 Over 1 but less than 5 years 21,034 22,582 Over 5 years 16,936 18,635 Total 46,754 49,768 There is no significant difference between the total future minimum lease payments and the present value of total future minimum lease payments as of March 31, 2018 and 2019. (2) Operating leases As a lessee The future minimum lease payments under non-cancellable operating lease contracts are as follows: (Millions of Yen) Year ended Year ended Within 1 year 11,371 9,965 Over 1 but less than 5 years 29,434 31,624 Over 5 years 4,994 6,638 Total 45,800 48,228 Operating lease expenses under non-cancellable operating lease contracts recognized during the years ended March 31, 2019 and 2018 amounted to 10,356 million yen and 9,597 million yen, respectively. As a lessor The future lease payments expected to be received under non-cancellable operating lease contracts are as follows: (Millions of Yen) Year ended Year ended Within 1 year 2,314 1,906 Over 1 but less than 5 years 8,326 6,549 Over 5 years 21,712 7,654 Total 32,353 16,110

Employee Benefits

Employee Benefits	12 Months Ended
	Mar. 31, 2019
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Employee Benefits	20. Employee Benefits (1) Overview of retirement benefit plans The retirement benefit plans that the Group offers to its employees include lump-sum retirement payment plans, defined benefit plans, and defined contribution plans. Under the lump-sum retirement payment plans, the Group makes lump-sum payments to eligible employees upon their retirement. The amount of benefits under these plans is determined mainly based on the employee’s base salary and years of service at retirement. The Group also has defined benefit plans that are corporate pension plans in compliance with the Defined-Benefit Corporate Pension Act of Japan and provides benefit payments to eligible employees over a certain period of time after retirement. The amount of benefits under these plans is determined mainly based on the employee’s base salary and years of service at retirement. The management of plan assets for defined benefit plans aims to maximize the value of the plan assets within an acceptable level of risk in order to ensure stable future pension benefit payments to the plan participants and qualified beneficiaries. Specifically, the plan establishes a medium and long-term investment portfolio taking into consideration of the characteristics of the plan assets and pension obligations. This investment portfolio is reviewed periodically and adjusted for changes in the market environment and funding position since initial assumptions has been set out. Under the defined contribution plans, the responsibility of the Company and its subsidiaries is limited to contributions based on the amount determined in the retirement benefits policies of each participating company. (2) Reconciliation of the present value of the defined benefit obligations The changes in the present value of the defined benefit obligations for the Group are as follows: (Millions of Yen) Year ended Year ended Balance at beginning of the year 619,280 650,749 Current service cost 34,137 34,168 Interest cost 2,610 2,591 Actuarial gains and losses 6,183 296 Past service cost (54 ) (5,700 ) Benefits paid (48,542 ) (55,624 ) Other 17,137 (7,199 ) Balance at end of the year 630,754 619,280 The weighted average duration of the defined benefit obligations for the years ended March 31, 2019 and 2018 is 11.9 years and 11.5 years, respectively. (3) Reconciliation of the fair value of the plan assets The changes in the fair value of the plan assets for the Group are as follows: (Millions of Yen) Year ended Year ended Balance at beginning of the year 554,671 545,072 Interest income 2,986 2,788 Return on plan assets, excluding interest income (457 ) 29,550 Employer contributions 13,903 13,765 Benefits paid (29,682 ) (34,637 ) Other (15,174 ) (1,866 ) Balance at end of the year 526,246 554,671 The Group expects to contribute 12,461 million yen to the defined benefit plans for the year ending March 31, 2020. (4) The components of the fair value of plan assets by asset category The components of the fair value of plan assets by asset category are as follows: (Millions of Yen) As of As of With quoted With no With quoted With no Bonds 80,469 — 83,441 — Equity investments 208,456 — 249,400 — Cash and cash equivalents 43,857 — 32,799 — General accounts at life insurance company — 126,547 — 123,396 Other — 66,915 — 65,633 Total 332,783 193,463 365,641 189,030 (5) Significant actuarial assumptions The significant actuarial assumptions used to determine the present value of defined benefit obligations for the Company are as follows: As of As of Discount rate 0.3 % 0.3 % (6) Sensitivity analysis The effects on defined benefit obligations of increase in the discount rates are as follows: (Millions of Yen) Year ended Year ended Effects of incremental increase in discount rate by 0.5% 33,151 million yen 32,049 million yen The sensitivity analysis assumes that other assumptions remain unchanged. (7) Defined contribution plans The amounts recognized as expenses for defined contribution plans are 6,557 million yen, 5,008 million yen and 4,926 million yen for the years ended March 31, 2019, 2018 and 2017, respectively. (8) Employee benefits expenses The Group incurred employee benefits expenses of 869,640 million yen, 831,273 million yen and 753,712 million yen for the years ended March 31, 2019, 2018 and 2017, respectively. These expenses are included in “Cost of sales” and “Selling, general and administrative expenses” in the consolidated statements of profit or loss. Salary, bonus, statutory health and welfare benefits and retirement benefits expenses are included in employee benefits expenses.

Equity and Other Equity Items

Equity and Other Equity Items	12 Months Ended
	Mar. 31, 2019
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Equity and Other Equity Items	21. Equity and Other Equity Items (1) Common stock and reserves The total number of shares authorized to be issued and shares outstanding are as follows: Number of shares Number of shares As of March 31, 2017 2,000,000 950,321 Changes — — As of March 31, 2018 2,000,000 950,321 Changes — — As of March 31, 2019 2,000,000 950,321 All the shares authorized to be issued and shares outstanding are without par value. Capital surplus Capital surplus comprises of amounts generated through capital transactions that are not recorded in common stock, and its primary component is capital reserves. The Companies Act of Japan stipulates that one-half or more of the proceeds from issuance of shares should be incorporated in common stock, and that the remainder shall be incorporated in capital reserve included in capital surplus. The act stipulates that the capital reserve may be incorporated in common stock upon resolution at the general meeting of shareholders. Retained earnings Retained earnings consist of legal reserves and accumulated earnings. The Companies Act of Japan provides that one-tenth of cash dividends be appropriated as capital reserve or legal reserve at the date of distribution until the total amount of these reserves equals one-fourth of common stock. Legal reserve may be utilized to cover capital losses upon resolution at the general meeting of shareholders. (2) Treasury stock The total number of treasury stock held by the Group is as follows: Number of shares As of March 31, 2017 67,674 Changes 36 As of March 31, 2018 67,710 Changes (37,912 ) As of March 31, 2019 29,797 The Company used 38,161 thousand shares of the treasury stock to acquire shares of Nisshin Steel through the share exchange on January 1, 2019.

Dividends

Dividends	12 Months Ended
	Mar. 31, 2019
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Dividends	22. Dividends The dividends paid by the Company are as follows: Year ended March 31, 2019 (1) Dividends paid Date of resolution Class of share Total amount of Dividends per Record date Effective date Shareholders’ meeting held on June 26, 2018 Ordinary shares 35,355 40 March 31, 2018 June 27, 2018 Board of directors meeting held on November 2, 2018 Ordinary shares 35,355 40 September 30, 2018 December 3, 2018 (2) Dividends that belong to the current consolidated reporting year but become effective in the subsequent consolidated reporting year Date of resolution Class of share Source of Total amount of Dividends per Record date Effective date Shareholders’ meeting held on June 25, 2019 Ordinary shares Retained 36,880 40 March 31, 2019 June 26, 2019 Year ended March 31, 2018 (1) Dividends paid Date of resolution Class of share Total amount of Dividends per Record date Effective date Shareholders’ meeting held on June 27, 2017 Ordinary shares 39,776 45 March 31, 2017 June 28, 2017 Board of directors meeting held on October 27, 2017 Ordinary shares 26,517 30 September 30, 2017 November 30, 2017 (2) Dividends that belong to the current consolidated reporting year but become effective in the subsequent consolidated reporting year Date of resolution Class of share Source of Total amount of Dividends per Record date Effective date Shareholders’ meeting held on June 26, 2018 Ordinary shares Retained 35,355 40 March 31, 2018 June 27, 2018 Year ended March 31, 2017 (3) Dividends paid Date of resolution Class of share Total amount of Dividends per Record date Effective date Shareholders’ meeting held on June 24, 2016 Ordinary shares 13,554 15 March 31, 2016 June 27, 2016 (4) Dividends that belong to the current consolidated reporting year but become effective in the subsequent consolidated reporting year Date of resolution Class of share Source of Total amount of Dividends per Record date Effective date Shareholders’ meeting held on June 27, 2017 Ordinary shares Retained 39,776 45 March 31, 2017 June 28, 2017

Revenue

Revenue	12 Months Ended
	Mar. 31, 2019
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Revenue	23. Revenue (1) Disaggregation of revenue Disaggregation of revenue from contracts with customers and its relationship with segment revenue are as follows. Year ended March 31, 2019 (Millions of Yen) Steelmaking Engineering Chemicals System Consolidated Japan 3,431,461 264,674 155,184 201,868 4,053,188 Asia 1,194,440 34,746 78,872 2,831 1,310,890 Middle East 113,180 2 319 — 113,502 Europe 142,335 20,645 4,426 66 167,473 North America 279,575 997 4,055 151 284,779 Central and South America 188,473 279 156 34 188,944 Africa 46,202 — 0 — 46,202 Pacific 12,963 — 0 — 12,964 Total 5,408,633 321,346 243,014 204,952 6,177,947 Revenue is classified based on the geographic location of customers and presented at the amount less adjustment of inter-segment transactions. (2) Contract balances (Millions of Yen) At beginning of the year As of Receivables 685,761 774,803 Contract assets 45,044 67,769 Contract liabilities 22,936 28,488 Receivables and contract assets are included in “Trade and Other Receivables” in the consolidated statement of financial position. Contract liabilities are included in “Other current liabilities” in the consolidated statement of financial position. The amount included in the contract liabilities as of April 1, 2018 and recognized as revenue for the year ended March 31, 2019 amounted to 20,099 million yen. The amount recognized as revenue for the year ended March 31, 2019 from performance obligations satisfied in previous periods is immaterial. (3) Transaction price allocated to the remaining performance obligation (Millions of Yen) As of March 31, 2019 Engineering and System Solutions Within 1 year 259,610 184,782 74,828 Over 1 year 202,262 170,569 31,693 Total 461,872 355,351 106,521 The above is included transaction price allocated to the remaining performance obligation whose original expected duration of performance obligation is one year or less and is presented at the amount less adjustment of inter-segment transactions. The Group applied the practical expedient and does not disclose the information with respect to Steelmaking and Steel Fabrication segments and Chemicals and Materials segments as original expected duration of performance obligation is mostly one year or less. (4) Assets recognized from the costs to obtain or fulfill a contract with a customer The Group’s incremental costs of obtaining a contract and costs to fulfill a contract with customer required to be recognized as assets are immaterial.

Selling, General and Administra

Selling, General and Administration Expenses	12 Months Ended
	Mar. 31, 2019
Text block [abstract]
Selling, General and Administration Expenses	24. Selling, General and Administration Expenses The components of selling, general and administrative expenses are as follows: (Millions of Yen) Year ended Year ended Year ended Transportation and storage 161,091 141,873 112,637 Salaries and bonuses 141,390 137,687 122,184 Retirement benefit costs 8,713 7,336 5,897 Research and development costs 58,621 61,019 54,912 Depreciation and amortization 8,693 10,064 7,138 Other 189,901 175,804 163,584 Total 568,409 533,787 466,351

Research and Development Costs

Research and Development Costs	12 Months Ended
	Mar. 31, 2019
Text block [abstract]
Research and Development Costs	25. Research and Development Costs The total amounts of research and development costs included in “Cost of sales” and “Selling, general and administrative expenses” are as follows: (Millions of Yen) Year ended Year ended Year ended Research and development costs 72,043 74,071 70,100

Other Operating Income and Othe

Other Operating Income and Other Operating Expenses	12 Months Ended
	Mar. 31, 2019
Text block [abstract]
Other Operating Income and Other Operating Expenses	26. Other Operating Income and Other Operating Expenses The components of “Other operating income” and “Other operating expenses” are as follows: (1) Other operating income (Millions of Yen) Year ended Year ended Year ended Dividends received 20,156 17,832 15,005 Foreign exchanges gains (net) 6,152 — — Other 76,296 73,689 47,102 Total 102,606 91,521 62,108 Dividend income is generated mainly from financial assets measured at fair value through other comprehensive income. (2) Other operating expenses (Millions of Yen) Year ended Year ended Year ended Foreign exchanges losses (net) — 3,976 9,310 Impairment losses — 18,075 — Losses on disposal of fixed assets 27,665 30,540 32,322 Other 42,455 46,181 39,539 Total 70,120 98,773 81,171

Losses on natural disaster

Losses on natural disaster	12 Months Ended
	Mar. 31, 2019
Investments accounted for using equity method [abstract]
Losses on natural disaster	27. Losses on natural disaster Losses related to weather related natural disasters were incurred during the year ended March 31, 2019. The nature of the losses represent costs on restoration, disposal of machinery and other related costs which amounted to 22,349 million yen.

Gains or losses from reorganiza

Gains or losses from reorganization	12 Months Ended
	Mar. 31, 2019
Text block [abstract]
Gains or losses from reorganization	28. Gains or losses from reorganization As part of its strategic initiative, the Company has realigned resource allocation to certain of its business and has incurred losses from reorganization. The reorganization losses are principally divided into impairment losses of 16,882 million yen, losses on withdrawal from businesses of 17,443 million yen and losses incurred to withdraw inactive facilities and other losses of 15,154 million yen for the year ended March 31, 2019. Impairment losses relate to goodwill and impairment of equity method investments due to changes in recoverable amounts as a result of reorganization of business activities. Refer to Note 30 “Impairment of Assets” for further discussion. Losses on withdrawal from businesses mainly consist of losses related to the pending withdrawal from large casting and forgings business operated by Japan Casting & Forging Corporation, an affiliate in the Steelmaking and Steel Fabrication segment, due to unfavorable business environment. Losses incurred to withdraw inactive facilities and others losses mainly consist of the termination and demolition losses of blast furnace of Wakayama Works which was replaced by a new facility in February 2019. Majority of the gains from reorganization for the year ended March 31, 2017 resulted from gain from the partial sale of shares of SUMCO Corporation, which was offset by losses from reorganization of Butt-welding Fittings Business of Nippon Steel & Sumikin Kikoh Company, Ltd., in the Steelmaking and Steel Fabrication segment.

Finance Income and Finance Cost

Finance Income and Finance Costs	12 Months Ended
	Mar. 31, 2019
Text block [abstract]
Finance Income and Finance Costs	29. Finance Income and Finance Costs The components of “Finance income” and “Finance costs” are as follows: (1) Finance income (Millions of Yen) Year ended Year ended Year ended Interest income 6,028 5,710 6,241 Other 76 1,933 81 Total 6,104 7,644 6,322 Interest income is generated mainly from financial assets measured at amortized cost. (2) Finance costs (Millions of Yen) Year ended Year ended Year ended Interest expense 19,133 21,339 19,292 Other 3,311 3,245 2,293 Total 22,445 24,584 21,586 Interest expense is generated mainly from financial liabilities measured at amortized cost.

Impairment of Assets

Impairment of Assets	12 Months Ended
	Mar. 31, 2019
Text block [abstract]
Impairment of Assets	30. Impairment of Assets (1) Impairment losses Year ended March 31, 2019 (Millions of Yen) Steelmaking and Engineering and Chemicals and System Solutions Adjustments Total 11,909 4,972 — — — 16,882 Impairment losses in the Steelmaking and Steel Fabrication segment were recognized mainly due to strategic realignments of its businesses in order to address unfavorable business environment. This includes the impairment loss of 5,990 million yen related to goodwill of a subsidiary which is in a business of manufacturing and distribution of railway wheels and axles in the U.S. This impairment loss was recognized due to the decision to reorganize the operation of certain business in the U.S. in the Steelmaking and Steel Fabrication segment. The recoverable amount of related assets was calculated based on the fair value less costs of disposal which was determined using the market approach and was categorized within Level 3 of the fair value hierarchy. Impairment loss of 5,919 million yen related to the investment accounted for using the equity method held by a subsidiary which operates mining business in Australia was recognized as a result of re-review of its investment plan. The recoverable amount related to this investment is calculated based on value-in-use using the discounted cash flow method with the pre-tax discounted rate of 8.0%. Impairment loss in the Engineering and Construction segment are recognized mainly due to unfavorable business environment. This goodwill related impairment loss was incurred by a subsidiary which operates environmental plant business in Europe. The recoverable amount of related assets was calculated based on value-in-use by using the discounted cash flow method with the pre-tax discounted rate of 8.0%. Year ended March 31, 2018 (Millions of Yen) Steelmaking and Engineering and Chemicals and System Solutions Adjustments Total 9,932 2,472 3,334 2,570 (234 ) 18,075 Impairment losses in the Steelmaking and Steel Fabrication segment are recognized mainly due to unfavorable business environment. This includes the impairment losses of 8,505 million yen recognized with respect to the operating assets held by a subsidiary in the U.S. which operates pipe business and the carrying amount of related assets was reduced to the recoverable amount of zero. The recoverable amount of related assets is calculated based on value-in-use using the discounted cash flow method. Impairment losses in the Engineering and Construction segment are recognized due to unfavorable business environment. This is arisen from the reduction in the carrying amount of goodwill acquired in business combinations of a subsidiary which operates environmental plant engineering business in Europe. The recoverable amount of related assets is calculated based on value-in-use using the discounted cash flow method with the pre-tax discounted rate of 8.0%. Impairment losses in the Chemicals and Materials segment are recognized due to unfavorable business environment. This is arisen from the reduction in the carrying amount of the operating assets held by a subsidiary which operates coal chemicals business in China. Impairment losses in the System Solutions segment are recognized by assessing the forecast of future earnings with respect to a part of data center assets. The recoverable amount of related assets is calculated based on the fair value less costs of disposal which is mainly based on real estate appraisals and was categorized within Level 3 of the fair value hierarchy. Year ended March 31, 2017 There are no material impairment losses occurred in the year ended March 31, 2017. (2) Impairment test of goodwill The breakdown of the carrying amount of goodwill by segment is as follows: (Millions of Yen) Operating segment As of As of Steelmaking and Steel Fabrication 44,477 28,596 Engineering and Construction 3,300 8,641 Chemicals and Materials — — System Solutions 5,025 5,025 Total 52,803 42,263 The recoverable amount of the cash-generating units to which the goodwill is allocated is calculated based on value-in-use or the fair value less costs of disposal. In measuring value in use, past experience and external evidence are reflected and the estimated future cash flows are discounted to the present value. The future cash flows are estimated based on a business plan approved by management, which covers a maximum period of five years, and a growth rate for the subsequent years. The discount rate is calculated based on the weighted average cost of capital of each cash-generating unit which is the pre-tax discounted rate of principally 8.0%.

Other Comprehensive Income

Other Comprehensive Income	12 Months Ended
	Mar. 31, 2019
Text block [abstract]
Other Comprehensive Income	31. Other Comprehensive Income The components of other comprehensive income are as follows: Year ended March 31, 2019 (Millions of Yen) Incurred during Reclassification Before tax Tax effect After tax Items that cannot be reclassified to profit or loss Changes in fair value of financial assets measured at fair value through other comprehensive income (138,361 ) — (138,361 ) 33,804 (104,557 ) Remeasurements of defined benefit assets (6,641 ) — (6,641 ) 3,109 (3,531 ) Share of other comprehensive income of investments accounted for using the equity method (2,953 ) — (2,953 ) — (2,953 ) Subtotal (147,956 ) — (147,956 ) 36,913 (111,042 ) Items that might be reclassified to profit or loss Changes in fair value of cash flow hedges 6,155 (4,234 ) 1,921 (398 ) 1,522 Foreign exchange differences on translation of foreign operations (42,391 ) (111 ) (42,502 ) 1,246 (41,256 ) Share of other comprehensive income of investments accounted for using the equity method (21,750 ) 62 (21,687 ) — (21,687 ) Subtotal (57,985 ) (4,283 ) (62,269 ) 847 (61,421 ) Total (205,942 ) (4,283 ) (210,225 ) 37,761 (172,464 ) “Incurred during the year” and “Reclassification” in shares of other comprehensive income of investments accounted for using the equity method are stated with the amount after tax effect. Year ended March 31, 2018 (Millions of Yen) Incurred during Reclassification Before tax Tax effect After tax Items that cannot be reclassified to profit or loss Changes in fair value of financial assets measured at fair value through other comprehensive income 94,274 — 94,274 (29,051 ) 65,222 Remeasurements of defined benefit assets 29,253 — 29,253 (9,831 ) 19,422 Share of other comprehensive income of investments accounted for using the equity method 5,125 — 5,125 — 5,125 Subtotal 128,653 — 128,653 (38,883 ) 89,770 Items that might be reclassified to profit or loss Changes in fair value of cash flow hedges (2,351 ) 4,678 2,326 (538 ) 1,788 Foreign exchange differences on translation of foreign operations 12,390 (215 ) 12,174 (1,582 ) 10,592 Share of other comprehensive income of investments accounted for using the equity method (2,488 ) (113 ) (2,602 ) — (2,602 ) Subtotal 7,550 4,349 11,899 (2,120 ) 9,778 Total 136,203 4,349 140,552 (41,003 ) 99,548 “Incurred during the year” and “Reclassification” in shares of other comprehensive income of investments accounted for using the equity method are stated with the amount after tax effect. Year ended March 31, 2017 (Millions of Yen) Incurred during Reclassification Before tax Tax effect After tax Items that cannot be reclassified to profit or loss Changes in fair value of financial assets measured at fair value through other comprehensive income 119,533 — 119,533 (33,263 ) 86,269 Remeasurements of defined benefit assets 33,791 — 33,791 (9,727 ) 24,063 Share of other comprehensive income of investments accounted for using the equity method 406 — 406 — 406 Subtotal 153,732 — 153,732 (42,991 ) 110,740 Items that might be reclassified to profit or loss Changes in fair value of cash flow hedges 5,404 8,533 13,937 (4,485 ) 9,452 Foreign exchange differences on translation of foreign operations (28,332 ) 2,551 (25,781 ) 702 (25,079 ) Share of other comprehensive income of investments accounted for using the equity method 8,008 1,854 9,863 — 9,863 Subtotal (14,919 ) 12,939 (1,980 ) (3,782 ) (5,763 ) Total 138,812 12,939 151,751 (46,774 ) 104,977 “Incurred during the year” and “Reclassification” in shares of other comprehensive income of investments accounted for using the equity method are stated with the amount after tax effect.

Earnings per Share

Earnings per Share	12 Months Ended
	Mar. 31, 2019
Text block [abstract]
Earnings per Share	32. Earnings per Share Profit for the year attributable to common shares of the parent is as follows: (Millions of Yen) Year ended Year ended Year ended Profit for the year attributable to owners of the parent 251,169 180,832 137,246 Profit for the year not attributable to ordinary equity holders of the parent — — — Profit for the year used to calculate basic earnings per share 251,169 180,832 137,246 Diluted earnings per share is not presented as there are no potential dilutive shares. The weighted average number of ordinary shares outstanding is as follows: (Shares) Year ended Year ended Year ended Weighted average number of ordinary shares outstanding 891,387,729 882,629,157 884,959,677

Financial Instruments

Financial Instruments	12 Months Ended
	Mar. 31, 2019
Text block [abstract]
Financial Instruments	33. Financial Instruments (1) Capital management Under the presumption that a certain level of financial stability is maintained, the Group has capital management policies which emphasize operational efficiency of invested capital, maximize corporate value by utilizing funds in investments (including investments in capital expenditure, research and development and M&A) which are expected to generate revenue which exceeds the cost of capital to enable sustainable growth and, at the same time, meet the demands of shareholders by providing returns to shareholders based on profits. The necessary funds to achieve this are primarily provided through cash flows from operating activities which are generated from maintaining and enhancing the Group’s earnings power, and the Group raises funds through borrowings from banks and the issuance of corporate bonds, as necessary. The Group identifies Return on Equity (“ROE”) and Debt Equity Ratio (“D/E ratio”) as key management indicators to achieve medium and long-term profit growth and stability of the financial base. ROE is calculated by dividing profit for the year attributable to owners of the parent by the equity attributable to owners of the parent. D/E ratio is calculated by dividing interest-bearing debts by the equity attributable to owners of the parent. As of As of ROE (%) 7.9 6.0 D/E Ratio (times) 0.73 0.69 There are no significant capital regulations which are applied to the Company. (2) Classification of financial instruments (a) Valuation techniques used to measure the fair value for the financial instruments with a carrying amount measured at fair value (i) Equity instruments The fair value of marketable equity instruments is measured using quoted market prices at the end of the reporting period. The fair value of non-marketable equity instruments is estimated using appropriate valuation techniques, such as the market approach. (ii) Derivatives The fair value of derivatives is measured with reference to prices provided by the counterparty and forward exchange rates. (b) Classification by levels in the fair value hierarchy The fair value hierarchy of financial instruments is classified from Level 1 to Level 3 as follows: Level 1: Fair value measured with quoted prices in active markets for identical assets or liabilities, Level 2: Fair value measured using inputs that are directly or indirectly observable for assets or liabilities other than those in Level 1, Level 3: Fair value measured using inputs that are not based on observable market data for assets or liabilities. (c) Method to measure the changes in fair value FVPL: Method of measuring changes in fair value through profit or loss FVOCI: Method of measuring changes in fair value through other comprehensive income (d) Carrying amounts of financial instruments by classification The carrying amounts of financial instruments by classification as of March 31, 2019 and 2018 are as follows: As of March 31, 2019 Financial assets (Millions of Yen) Carrying amount Amortized cost Fair value Total FVPL FVOCI Current assets Cash and cash equivalents 163,176 — — 163,176 Trade and other receivables 900,563 — — 900,563 Other financial assets 12,844 590 3,480 16,915 Derivatives — 590 3,480 4,071 Debt instruments 12,844 — — 12,844 Non-current assets Other financial assets 84,211 — 728,456 812,668 Equity instruments — — 718,470 718,470 Derivatives — — 9,985 9,985 Debt instruments 84,211 — — 84,211 Derivatives included in FVOCI represent the effective portion of hedging instruments designated in cash flow hedge. The carrying amount of “trade and other receivables” in the table above does not include the assets recognized in accordance with IFRS 15 which amounts to 67,769 million yen. Financial liabilities (Millions of Yen) Carrying amount Amortized cost Fair value Total FVPL FVOCI Current liabilities Trade and other payables 1,611,403 — — 1,611,403 Bonds and borrowings 506,571 — — 506,571 Other financial liabilities Derivatives — 258 758 1,017 Non-current liabilities Bonds and borrowings 1,815,905 — — 1,815,905 Other financial liabilities Derivatives — — 6,501 6,501 Other non-current liabilities 142,149 — — 142,149 Derivatives included in FVOCI represent the effective portion of hedging instruments designated in cash flow hedge. The carrying amount of “other non-current liabilities” in the table above does not include the liabilities recognized in accordance with IAS 19 which amounts to 24,085 million yen. As of March 31, 2018 Financial assets (Millions of Yen) Carrying amount Amortized cost Fair value Total FVPL FVOCI Current assets Cash and cash equivalents 142,869 — — 142,869 Trade and other receivables 832,040 — — 832,040 Other financial assets 12,351 61 6,765 19,178 Derivatives — 61 6,765 6,827 Debt instruments 12,351 — — 12,351 Non-current assets Other financial assets 74,538 — 933,088 1,007,627 Equity instruments — — 926,465 926,465 Derivatives — — 6,623 6,623 Debt instruments 74,538 — — 74,538 Derivatives included in FVOCI represent the effective portion of hedging instruments designated in cash flow hedge. Financial liabilities (Millions of Yen) Carrying amount Amortized cost Fair value Total FVPL FVOCI Current liabilities Trade and other payables 1,580,597 — — 1,580,597 Bonds and borrowings 496,833 — — 496,833 Other financial liabilities Derivatives — 329 344 674 Non-current liabilities Bonds and borrowings 1,611,153 — — 1,611,153 Other financial liabilities Derivatives — — 6,572 6,572 Other non-current liabilities 120,156 — — 120,156 Derivatives included in FVOCI represent the effective portion of hedging instruments designated in cash flow hedge. The carrying amount of “other non-current liabilities” in the table above does not include the liabilities recognized in accordance with IAS 19 which amounts to 22,971 million yen. (e) Financial instruments measured at fair value The tables below represent the financial instruments measured at fair value on a recurring basis by level as of March 31, 2019 and March 31, 2018. As of March 31, 2019 Financial assets measured at fair value (Millions of Yen) Level 1 Level 2 Level 3 Total FVPL Other financial assets Derivatives — 590 — 590 FVOCI Other financial assets Equity instruments 638,768 — 79,702 718,470 Derivatives — 13,466 — 13,466 Financial liabilities measured at fair value (Millions of Yen) Level 1 Level 2 Level 3 Total FVPL Other financial liabilities Derivatives — 258 — 258 FVOCI Other financial liabilities Derivatives — 7,260 — 7,260 Derivatives included in FVOCI represent the effective portion of hedging instruments designated in cash flow hedge. As of March 31, 2018 Financial assets measured at fair value (Millions of Yen) Level 1 Level 2 Level 3 Total FVPL Other financial assets Derivatives — 61 — 61 FVOCI Other financial assets Equity instruments 847,645 — 78,819 926,465 Derivatives — 13,388 — 13,388 Financial liabilities measured at fair value (Millions of Yen) Level 1 Level 2 Level 3 Total FVPL Other financial liabilities Derivatives — 329 — 329 FVOCI Other financial liabilities Derivatives — 6,917 — 6,917 Derivatives included in FVOCI represent the effective portion of hedging instruments designated in cash flow hedge. The changes of equity instruments measured at Level 3 are as follows: (Millions of Yen) Year ended Year ended Balance at beginning of the year 78,819 83,237 Net changes in fair value 1,122 1,197 Acquisitions 116 54 Sale / settlements (641 ) (2,106 ) Other 286 (3,562 ) Balance at end of the year 79,702 78,819 (f) Equity instruments measured at fair value through other comprehensive income (“FVOCI”) (i) Fair value of significant equity instruments measured at FVOCI by name As of Amount Toyota Motor Corporation 80,312 POSCO 70,952 Suzuki Motor Corporation 38,006 Recruit Holdings 37,110 Central Japan Railway Company 30,633 As of Amount POSCO 96,996 Toyota Motor Corporation 79,778 SUMCO Corporation 64,783 Suzuki Motor Corporation 44,462 Vallourec S.A. 37,466 (ii) Fair value at the time of derecognition for assets that were derecognized and cumulative gains or losses on disposal The Group derecognizes certain financial assets that are measured at fair value through other comprehensive income as a result of disposals through sale occurring as a result of review of business relationships. (Millions of Yen) Year ended Year ended Fair value at the time of derecognition 83,726 37,532 Cumulative gains or losses on disposal (net of tax) 14,679 6,542 (iii) Dividends recognized for the equity investments measured at FVOCI during the reporting period (Millions of Yen) Year ended Year ended Investment derecognized in the reporting period 2,168 865 Investment held at the end of reporting period 17,988 16,967 Total 20,156 17,832 (3) Fair value of financial instruments Financial instruments measured at amortized cost The fair value of financial assets and financial liabilities measured at amortized cost is as follows: (Millions of Yen) As of March 31, 2019 Carrying Fair value Level 1 Level 2 Level 3 Financial assets (Current) Other financial assets Debt instruments 12,844 9,498 0 3,345 Financial assets (Non-current) Other financial assets Debt instruments 84,211 11 7,512 76,699 Financial liabilities (Current) Bonds and borrowings 506,571 60,386 — 446,571 Financial liabilities (Non-current) Bonds and borrowings 1,815,905 224,669 — 1,618,043 (Millions of Yen) As of March 31, 2018 Carrying Fair value Level 1 Level 2 Level 3 Financial assets (Current) Other financial assets Debt instruments 12,351 1,233 3,103 8,018 Financial assets (Non-current) Other financial assets Debt instruments 74,538 23 5,497 69,015 Financial liabilities (Current) Bonds and borrowings 496,833 86,080 — 411,133 Financial liabilities (Non-current) Bonds and borrowings 1,611,153 215,686 — 1,415,613 The tables do not include financial assets and liabilities measured at amortized cost whose fair values approximate their carrying amounts. Valuation techniques used to measure the fair value of financial instruments measured at amortized cost - The fair value of a marketable financial asset is measured with reference to its market price. - The fair value of a non-marketable financial asset is measured with reference to the price quoted by financial institutions. - The fair value of a bond is measured with reference to its market price. - The fair value of a borrowing is measured at the present value of the total amounts of principal and interest discounted by the Group’s incremental borrowing rate with a similar term. (4) Risk management The Group is exposed to various financial risks (market risk, credit risk and liquidity risk) arising from its business activities and implements risk management processes to minimize these financial risks. (a) Market risk management (i) Foreign currency risk Trade receivables denominated in foreign currencies arising from exports of products are exposed to foreign currency risk. Trade payables, notes payable and other payables are, in principle, come due within one year. Certain trade payables are denominated in foreign currencies arising from imports of raw materials and exposed to foreign currency risk. The Group enters into forward exchange contracts and currency swaps to hedge foreign exchange risk arising from sales and capital transactions and investing and financing activities of the Group. Derivative transactions are executed in accordance with the internal derivative transaction policy. According to the internal l derivative transaction policy, the policy for entering into a derivative transaction of financial instruments is discussed and approved by the Financial Management Committee and reported as necessary at the Board of Directors’ meeting. Subsequently the Financial Controller approves the implementation of derivatives within the approved authority limits and reports that transaction amounts as well as gains or losses arising from derivative transactions to the Financial Management Committee on a regular basis. The Group’s principal foreign currency risk exposures for the years ended March 31, 2018 and 2019 are as follows. (Millions of USD) As of As of Net exposure (liability) 78 (174 ) Impacts on profit before income taxes in the consolidated statements of profit or loss if Japanese yen were to appreciate by 1% against the U.S. Dollar at the end of the reporting period are as follows. In this analysis, the impacts on the assets and liabilities denominated in foreign currencies as of March 31, 2018 and 2019 are estimated by assuming that variables, such as outstanding balances and interest rates, are constant. (Millions of Yen) Year ended Year ended Impacts on profit before income taxes (86 ) 185 (ii) Interest rate risk Certain bonds and long-term borrowings are floating-rates debts. The interest expenses vary depending on interest rates. The Group enters into interest rate swap contracts to mitigate the risk of interest rate fluctuations. Impacts on income taxes in the consolidated statements of profit or loss if interest rates were to increase by 1% at the end of the reporting period are as follows. In this analysis, all other variables are assumed to be constant. (Millions of Yen) Year ended Year ended Impacts on profit before income taxes (6,043 ) (5,787 ) (iii) Market price fluctuation risk Marketable equity instruments mainly represent the shares of trade counterparties for which are purchased to strengthen business alliances and are exposed to market price fluctuation risk. The Group monitors the market price on a regular basis and regularly evaluates the necessity to retain the respective investments. (b) Credit risk management In accordance with the internal credit management policy, the Group shares customer credit records with related departments, and provides for credit protection measures as necessary. Trade receivables, including notes and accounts receivable, are exposed to the credit risk of customers. The Group limits transactions to customers who are also the principal suppliers of the Group such that the trade receivables due from the customers may be offset with the trade payables and borrowings, or to customers with high credit ratings where and the Group concludes that there are limited credit risks. (i) Credit risk exposure The total amount of the contractual amounts of financial guarantees and loan commitments and the carrying amount of financial assets (net of impairment) represents its maximum exposure to credit risk without taking into account of any collaterals held. For the credit risk exposure, the Group recognizes the allowance for doubtful accounts by measuring the lifetime expected credit losses. Allowance for doubtful accounts with respect to trade receivables is assessed by multiplying the carrying amount of trade receivables by the rate of historical credit losses on an individual basis. (ii) Financial assets subject to allowance for doubtful accounts The aging of trade and other receivables is as follows: (Millions of Yen) Days past due As of As of Current 964,845 831,985 Within 90 days 4,991 1,684 Over 90 days and within 1 year 729 363 Over 1 year 173 108 Total 970,740 834,142 (iii) Changes in allowance for doubtful accounts The changes in allowance for doubtful accounts are as follows: (Millions of Yen) Year ended Year ended Balance at beginning of the year 5,878 5,854 Increase during the year 1,776 1,529 Decrease during the year (696 ) (1,513 ) Other 183 7 Balance at end of the year 7,142 5,878 (c) Liquidity risk management The Group manages its liquidity risk on financing activities (the risk that debts cannot be paid by the due dates) by preparing and regularly updating a cash flow forecast based on the reports obtained from respective departments. Furthermore, the Group has a line of credit to cover for unforeseen circumstances. The Group has entered into commitment line agreements with financial institutions to manage its working capital requirements effectively. As of March 31, 2019, the balance of borrowings related to those agreements was zero. The available credit balance under these agreements was 666,096 million yen and 650,933 million yen as of March 31, 2019, and 2018, respectively. The figures below show the remaining amount of the Group’s financial liabilities by contractual maturity at the end of the reporting period, but do not contain financial guarantees where the Group is obligated to make payments on the obligations arising from financial guarantee contracts. The maximum amounts of guarantees that are extended by the Group are described in Note 34 “Loan Guarantees”. As of March 31, 2019 (Millions of Yen) Carrying Total Within 1 year Over 1 year but within 5 years Over 5 years Trade and other payables 1,611,403 1,611,403 1,611,403 — — Borrowings 1,922,476 1,922,476 326,571 657,235 938,670 Bonds 280,000 280,000 60,000 100,000 120,000 Lease liabilities 46,754 46,754 8,783 21,034 16,936 Commercial paper 120,000 120,000 120,000 — — Derivatives 7,519 7,019 2,656 4,363 — Total 3,988,154 3,987,654 2,129,414 782,633 1,075,606 As of March 31, 2018 (Millions of Yen) Carrying Total Within 1 year Over 1 year but within 5 years Over 5 years Trade and other payables 1,580,597 1,580,597 1,580,597 — — Borrowings 1,723,290 1,723,290 322,133 584,131 817,024 Bonds 295,696 295,700 85,700 140,000 70,000 Lease liabilities 49,768 49,768 8,550 22,582 18,635 Commercial paper 89,000 89,000 89,000 — — Derivatives 7,246 8,080 2,279 5,478 323 Total 3,745,600 3,746,436 2,088,260 752,192 905,983 (5) Derivatives (a) Impacts on the consolidated statement of financial position (i) Derivative assets and liabilities designated as hedging instruments As of March 31, 2019 (Millions of Yen) Types of hedges Derivative assets and liabilities Notional Carrying amount Total Settlement in Assets Liabilities Cash flow hedge Foreign exchange forward contract 217,369 6,762 1,752 750 Interest rate swap 264,704 252,848 730 6,509 Currency swap 67,353 66,280 9,462 — Commodity swap 2,529 1,058 1,519 — Total 551,957 326,949 13,466 7,260 As of March 31, 2018 (Millions of Yen) Types of hedges Derivative assets and liabilities Notional Carrying amount Total Settlement in Assets Liabilities Cash flow hedge Foreign exchange forward contract 246,189 9,113 1,069 303 Interest rate swap 275,939 258,741 601 6,613 Currency swap 83,244 67,353 11,665 — Commodity swap 321 217 52 — Total 605,695 335,425 13,388 6,917 The carrying amount (fair value) of derivative assets are included in “Other financial assets”. The carrying amount (fair value) of derivative liabilities are included in “Other financial liabilities”. The changes in the fair value of the hedged item that are used as the basis for recognition of the ineffective portion is not disclosed as the amount is immaterial. (ii) Derivative assets and liabilities not designated as hedges (Millions of Yen) As of As of Assets Liabilities Assets Liabilities Foreign exchange forward contract 492 248 4 381 Interest swap — — 2 — Currency swap 97 10 118 11 Total 590 258 124 392 (b) Changes in fair value of cash flow hedges The changes in fair value of hedging instruments designated as cash flow hedges of the Group recognized in other comprehensive income in the consolidated statements of comprehensive income or loss are as follows. Year ended March 31, 2019 (Millions of Yen) Risk classification Beginning of Changes in fair Amount End of the The account in which the Foreign currency risk 426 4,407 (4,186 ) 646 Other operating income/Other operating expenses Interest rate risk (5,559 ) 228 5 (5,326 ) Finance income/Finance costs Other 52 1,519 (52 ) 1,519 — Total (5,080 ) 6,155 (4,234 ) (3,159 ) Year ended March 31, 2018 (Millions of Yen) Risk classification Beginning of Changes in fair Amount End of the The account in which the Foreign currency risk (682 ) (3,626 ) 4,734 426 Other operating income/Other operating expenses Interest rate risk (6,762 ) 1,222 (18 ) (5,559 ) Finance income/Finance costs Other 37 52 (37 ) 52 — Total (7,407 ) (2,351 ) 4,678 (5,080 )

Related Parties

Related Parties	12 Months Ended
	Mar. 31, 2019
Text block [abstract]
Related Parties	34. Related Parties (1) Related party transactions Details of significant transactions with related parties are as follows: Year ended March 31, 2019 (Millions of Yen) Category Name Description of Amount Account Outstanding Associate Nippon Steel & Sumikin Bussan Corporation Sells steel products 1,170,241 Trade and other receivables 46,251 The terms and conditions applied to related party transactions are determined based on terms equivalent to those that prevail in arm’s length transactions. Year ended March 31, 2018 (Millions of Yen) Category Name Description of Amount Account Outstanding Associate Nippon Steel & Sumikin Bussan Corporation Sells steel products 849,244 Trade and other receivables 39,236 The terms and conditions applied to related party transactions are determined based on terms equivalent to those that prevail in arm’s length transactions. (2) Key management personnel compensation Compensation paid to the directors of the Group is as follows: (Millions of Yen) Year ended Year ended Year ended Salary 935 857 964

Commitments

Commitments	12 Months Ended
	Mar. 31, 2019
Text block [abstract]
Commitments	35. Commitments Significant commitments related to the acquisition of assets are as follows: (Millions of Yen) As of As of Contractual commitments related to acquisition of property, plant and equipment and intangible assets 393,230 316,808

Loan Guarantees

Loan Guarantees	12 Months Ended
	Mar. 31, 2019
Investments accounted for using equity method [abstract]
Loan Guarantees	36. Loan Guarantees The Group provides guarantees for the bank loans of its joint ventures and associates which would require the Group to repay the loan in the event of a default. (Millions of Yen) As of As of Guarantees for the bank loans of joint ventures and associates 62,506 82,721

Subsequent Events

Subsequent Events	12 Months Ended
	Mar. 31, 2019
Text block [abstract]
Subsequent Events	37. Subsequent Events There are no material subsequent events.

Significant Accounting Polici_2

Significant Accounting Policies (Policies)	12 Months Ended
	Mar. 31, 2019
Text block [abstract]
Basis of consolidation	(1) Basis of consolidation (a) Subsidiaries Subsidiaries are entities controlled by the Group. The Group controls an entity when it is exposed, or has rights to, variable returns from its involvement with the entity and has the ability to affect those returns through its power over the entity. The financial statements of subsidiaries are included in the consolidated financial statements from the date when control is obtained until the date when control is lost. If the Group loses control of a subsidiary, any gain or loss resulting from the loss of control is recognized in profit or loss. Changes in the Group’s interest in a subsidiary not resulting in a loss of control are accounted for as equity transactions, and the difference between the adjustment to the non-controlling When the accounting policies of the subsidiaries are different from those of the Group, the financial statements of subsidiaries are adjusted to ensure that the accounting policies are consistent with those of the Group. All intragroup balances, transaction amounts and unrealized gains and losses arising from intragroup transactions are eliminated in full in preparing the consolidated financial statements. Intragroup losses are eliminated in full except to the extent that the underlying asset is impaired. (b) Investments in associates An associate is an entity over which the Group has significant influence, which is the power to participate in the financial and operating policy decisions of the investee but there are no control. In principle, it is presumed that the Group has significant influence over an investee when the Group holds 20% or more but no more than 50% of the voting rights of the investee. An investee is determined as an associate when the Group has significant influence over it in one or more ways, not only the ratio of the voting rights, but also through participation in the policy-making progress and other right. An investment in an associate is accounted for under the equity method from the date when the Group has significant influence over it until the date when the significant influence is lost. Under the equity method, the investment is initially recognized at cost, and any excess of the Group’s share of the acquisition-date fair value of the investee’s identifiable net assets over the cost of the investment is recognized as goodwill that is included in the carrying amount of the investment. Thereafter, the investment is adjusted for the change in the Group’s share of the investee’s profit or loss and other comprehensive income. When the Group’s share of losses exceeds its interest in the associate, the Group’s interest is reduced to zero and recognition of further losses over the carrying amount of the investment is discontinued except to the extent that the Group assumes obligations or makes payments on behalf of the investee. When the Group ceases to have significant influence over an associate and discontinues the use of the equity method, gain or loss arising from discontinuance of the use of the equity method is recognized in profit or loss. Goodwill arising from the acquisition of an associate forms a part of the carrying amount of investments in the associate and is not separately recognized. Therefore, the goodwill of investment in an associate is not subject to impairment test separately. However, whenever there is any possibility that an investment in an associate may be impaired, the entire carrying amount of the investment is tested for impairment as a single asset. Regarding impairment of goodwill, refer to (10) “Impairment of non-financial (c) Joint arrangements The Group determines the type of a joint arrangement in which it is involved by considering its rights and obligations arising from the arrangement. When the parties that have joint control of an arrangement have rights to the assets, and obligations for the liabilities, relating to the arrangement, the arrangement is classified as a joint operation. When the parties that collectively control the arrangement have rights to the net assets of the arrangement and decisions about the relevant activities require the unanimous consent of those parties, that arrangement is classified as a joint venture. (d) Scope of consolidation and Application of equity method Number of consolidated subsidiaries: 420 companies At the end of fiscal year 2018, the scope of consolidation expanded by 46 companies, including 45 newly acquired companies and 1 newly established company. 19 companies, mainly 8 liquidations and 6 merged companies, were eliminated from the scope of consolidation during the fiscal year ended March 31, 2019. Number of equity-method affiliates (associates, jointly controlled businesses and jointly controlled companies) were 119 companies During the consolidated fiscal year 4 companies were added and 8 companies were removed from the scope of equity-method affiliates.
Business combinations	(2) Business combinations Business combinations are accounted for using the acquisition method when control is obtained. The identifiable assets acquired and the liabilities assumed of the acquiree are recognized at fair value as of the acquisition date. When the total of consideration transferred in business combinations and amount of non-controlling non-controlling The consideration transferred for the acquisition is measured as the total of fair value of the assets transferred, the liabilities incurred to former owners of the acquiree and the equity interests issued by the acquirer. In addition, the fair value of equity interest in the acquiree that the Group held before the date of obtaining control is included in the consideration transferred for a business combination achieved in stages. Acquisition costs attributable to a business combination are recognized as expenses as incurred. Non-controlling non-controlling acquisition-by-acquisition The components of profit or loss and other comprehensive income are attributed to owners of the parent and non-controlling interests based on the proportionate shares held.
Foreign currency translation	(3) Foreign currency translation (a) Functional currency and presentation currency The financial statements of each Group entity are presented in its functional currency that is the currency of the primary economic environment in which the entity operates. The consolidated financial statements are presented in Japanese yen, which is the functional currency of the Company. (b) Foreign currency transactions Foreign currency transactions are translated into the functional currency using the spot exchange rate at the transaction date or using the foreign exchange rate that approximates such rate. Foreign currency monetary items at the end of each reporting period are translated into the functional currency using the exchange rate at the end of each reporting period. Non-monetary Non-monetary (c) Foreign operations The financial performance and financial position of all of foreign operations which use a functional currency other than the presentation currency are translated into the presentation currency of the Company using the following exchange rates: (i) Assets and liabilities are translated using the exchange rates at the reporting date (ii) Income and expenses are translated at average exchange rates (iii) All resulting exchange differences arising from translation of foreign operations are recognized in other comprehensive income. When a foreign operation is disposed of, the cumulative amount of the exchange differences recognized in other comprehensive income is reclassified to profit or loss.
Financial instruments	(4) Financial instruments (a) Non-derivative (i) Recognition and measurement The Group recognizes financial assets when it becomes a party to the contractual provisions of the assets. Financial assets purchased or sold in a regular way are recognized on the trade date. Financial assets other than derivative financial instruments are classified at initial recognition as those measured at amortized cost or at fair value through other comprehensive income. Financial assets measured at amortized cost and fair value through other comprehensive income are initially recognized at their fair value plus transaction costs that are directly attributable to the acquisition of the assets. Financial assets measured at amortized cost Financial assets are classified as financial assets measured at amortized cost only if the assets are held within the Group’s business model with an objective of collecting contractual cash flows, and if the contractual terms of the financial assets give rise on specified dates to cash flows that are solely payments of principal and interest on the principal amount outstanding. However, the trade receivables that do not contain a significant financing component are recognized initially at their transaction price. Financial assets measured at fair value through other comprehensive income For certain equity instruments held primarily for the purpose of maintaining or strengthening business relationship with investees, the Group designates these instruments as financial assets measured at fair value through other comprehensive income at initial recognition. Subsequent changes in fair value are recognized in other comprehensive income. When these financial assets are derecognized or significant deterioration of fair value occurs, a gain or loss accumulated in other comprehensive income is reclassified to retained earnings. Dividends from the financial assets measured at fair value through other comprehensive income are recognized in profit or loss when the Group’s right to receive dividends is established. (ii) Derecognition Financial assets are derecognized when the contractual rights to the cash flows from the financial assets expire, or when the Group transfers the financial assets and substantially all the risks and rewards of ownership of the assets to another party. (iii) Impairment of financial assets measured at amortized cost The Group assesses expected credit loss at the end of each reporting period for the impairment of financial assets measured at amortized cost. The loss allowance is measured at an amount equal to the lifetime expected credit losses for trade receivables and financial assets with a significant increase in credit risk since initial recognition. The Group determines whether credit risk has significantly increased based on changes in the risk of a default occurring on the financial assets. When determining whether there are changes in the risk of a default occurring on the financial assets, the Group considers the following; • Significant deterioration in the financial conditions of an issuer or a borrower; • A breach of contract, such as default or past-due • It has become probable that a borrower will enter into bankruptcy or other financial reorganization (b) Non-derivative (i) Recognition and measurement Financial liabilities other than derivatives are classified as financial liabilities measured at amortized cost. (ii) Derecognition The Group derecognizes financial liabilities when the obligation specified in the contract is discharged, cancelled or expires. (c) Offsetting of financial instruments Financial assets and financial liabilities are offset and the net amount is presented in the consolidated statement of financial position only when the Group currently has a legally enforceable right to offset the recognized amounts and intends either to settle on a net basis or to realize the assets and settle the liabilities simultaneously. (d) Derivatives and hedge accounting The Group utilizes derivatives, including foreign exchange forward contracts, interest rate swaps and currency swaps, to hedge foreign currency risk and interest rate risk. These derivatives are initially recognized at fair value when the contract is entered into, and are subsequently measured at fair value. Changes in fair value of derivatives are recognized in profit or loss. However, the effective portion of cash flow hedges is recognized in other comprehensive income. The Group formally documents relationships between hedging instruments and hedged items, as well as its risk management objective and strategies for undertaking various hedge transactions in an internal rule titled “Administrative Provisions on Transactions of Derivative Instruments”. The rule stipulates that derivative transactions are conducted only for the purpose of mitigating risks arising from the Group’s principal business activities (including forecast transactions) and the trading of derivatives for speculative purposes is prohibited. The Group evaluates whether the derivatives designated as a hedging instrument offsets changes in fair value or the cash flows of the hedged items to a great extent when designating a hedging relationship and on an ongoing basis. A hedging relationship that qualifies for hedge accounting is classified and accounted for as follows: (i) Fair value hedges Changes in fair value of derivative as a hedging instrument are recognized in profit or loss. Changes in fair value of a hedged item adjust the carrying amount of the hedged item and are recognized in profit or loss. (ii) Cash flow hedges The effective portion of changes in fair value of derivative as a hedging instrument is recognized in other comprehensive income. Any ineffective portion of changes in fair value of derivative as the hedging instrument is recognized in profit or loss. The amount accumulated in other comprehensive income is reclassified to profit or loss when the hedged transactions affect profit or loss. When a hedged item results in the recognition of a non-financial non-financial non-financial non-financial
Cash and cash equivalents	(5) Cash and cash equivalents Cash and cash equivalents comprises of cash on hand, bank deposits available for withdrawal on demand, and short-term investments with the maturity of three months or less from the acquisition date, that are readily convertible to cash and subject to an insignificant risk of changes in value.
Inventories	(6) Inventories Inventories are measured at the lower of cost or net realizable value. The cost of inventories is measured based on the weighted average method, and comprises of all costs of purchasing and processing as well as other costs incurred in bringing the inventories to their present location and condition. Net realizable value represents the estimated selling price in the ordinary course of business less the estimated costs of completion and the estimated costs necessary to make the sale.
Property, plant and equipment	(7) Property, plant and equipment (a) Recognition and measurement Property, plant and equipment is initially measured at cost and presented at cost less accumulated depreciation and impairment losses. Acquisition cost includes costs directly attributable to the acquisition of the asset and costs of dismantling, removing and restoration of the asset. (b) Depreciation Depreciation of property, plant and equipment is mainly computed by the declining-balance method over the estimated useful lives of each component based on the depreciable amount, except for land and other non-depreciable The estimated useful lives of major property, plant and equipment are as follows: •  Buildings: Principally 31 years •  Machinery: Principally 14 years The depreciation methods, estimated useful lives and residual values are reviewed at the end of each reporting period, and modified as necessary.
Goodwill and intangible assets	(8) Goodwill and intangible assets Intangible assets are measured at cost. Intangible assets with finite useful lives are presented at cost less accumulated amortization and impairment losses. Goodwill and intangible assets with indefinite useful lives are presented at cost less accumulated impairment losses. (a) Goodwill When the total of consideration transferred in business combinations and amount of non-controlling Goodwill is not amortized and is allocated to cash-generating units or groups of cash-generating units. Regarding accounting policy for impairment of goodwill, refer to (10) “Impairment of non-financial (b) Intangible assets Intangible assets acquired separately are measured at cost at the date of initial recognition. The costs of intangible assets acquired in business combinations are measured at fair value at the acquisition date. Intangible assets with finite useful lives are presented at cost less accumulated amortization and impairment losses. Expenditures related to internally generated intangible assets are recognized as expenses when incurred, unless development expenses meet the criteria for capitalization. (c) Amortization Amortization of intangible assets with finite useful lives is recognized as an expense by the straight-line method over their estimated useful lives from the date when the assets are available for their intended use. The amortization methods and useful lives are reviewed at the end of each reporting period, and modified as necessary. The estimated useful lives of major intangible assets with finite useful lives are as follows: •  Software: Principally 5 years •  Mining rights: Principally 25 years Intangible assets with indefinite useful lives and intangible assets not yet available for use are not amortized. (d) Expenditure on research and development activities Expenditure on research activities is recognized in profit or loss as incurred. Development expenditure is capitalized only if the expenditure can be measured reliably, the product or process is technically and commercially feasible, future economic benefits are probable and the Group intends to and has sufficient resources to complete the development and to use or sell the asset. Otherwise, it is recognized in profit or loss as incurred.
Leases	(9) Leases The Group determines whether an arrangement is, or contains, a lease based on the substance of the arrangement as of the commencement date of the lease. For the substance of the arrangement, it makes an assessment of whether the fulfillment of the arrangement is dependent on the use of a specific asset or group of assets, and whether a right to use of the asset is transferred under the arrangement. A lease is classified as a finance lease, if all the risks and rewards of ownership of an asset are substantially transferred to the Group. Otherwise, a lease is classified as an operating lease. (a) Finance lease Lease assets and lease liabilities are initially recognized at the lower of fair value at the commencement of the lease or present value of the minimum lease payments. If it is reasonably certain that ownership will be transferred to a lessee by the end of the lease term, the leased asset is depreciated principally by the declining-balance method over the estimated useful life of the asset. Otherwise, the asset is depreciated over the shorter of the estimated useful life or the lease term. (b) Operating lease Lease payments under an operating lease are recognized in profit or loss on a straight-line basis over the relevant lease term.
Impairment of non-financial assets	(10) Impairment of non-financial For the non-financial The recoverable amount of an asset or a cash-generating unit is the higher of its fair value less costs to sell and its value in use. When the recoverable amount of the individual asset cannot be estimated, the Group estimates the recoverable amount of the cash-generating unit or the group of cash-generating units to which the asset belongs. The value in use is calculated by discounting the estimated future cash flows to the present value, and a pre-tax The cash-generating unit or the group of cash-generating units to which goodwill is allocated is the lowest level monitored for internal management purposes, and is not larger than an operating segment. As corporate assets do not independently generate cash inflows, when there is an indication that a corporate asset may be impaired, an impairment test is performed based on the recoverable amount of the cash-generating unit or the group of cash-generating units to which such corporate asset belongs. If the recoverable amount of the asset or the cash-generating unit is less than the carrying amount, the carrying amount of the asset is reduced to its recoverable amount and an impairment loss is recognized. The impairment loss recognized with respect to the cash-generating unit is allocated first to reduce the carrying amount of any goodwill allocated to the cash-generating unit, and then to reduce other assets of the unit on a pro-rata An impairment loss is reversed if there are indications that an impairment loss recognized in prior periods for an asset other than goodwill may no longer exist or may have decreased and the recoverable amount of the asset is greater than its carrying amount. The amount to be reversed would not exceed its carrying amount that would have been determined had no impairment loss been recognized for the asset in prior years. An impairment loss recognized in goodwill is not reversed.
Employee benefits	(11) Employee benefits Employee benefits include short-term employee benefits, retirement benefits, and other long-term employee benefits. (a) Short-term employee benefits Short-term employee benefit obligations are measured on an undiscounted basis and are recognized as expenses when the related service is provided. A liability is recognized for the amount expected to be paid under short-term cash incentive plans if the Group has a present legal or constructive obligation to pay in exchange for services provided by the employees in the prior period, and such obligation can be reliably estimated. (b) Retirement benefits Retirement benefit plans comprise of defined benefit corporate pension plans, defined contribution plans, and lump-sum (i) Defined benefit corporate pension plans and lump-sum The net defined benefit liabilities or assets of defined benefit plans are recognized as the present value of defined benefit obligations less the fair value of any plan assets. The present value of defined benefit obligations is calculated annually by qualified actuaries using the projected unit credit method. The discount rates are based on the market yields of high quality corporate bonds at the end of each reporting period that have terms consistent with the discount period, which is established as the estimated term of the retirement benefit obligations through to the estimated dates for payments of future benefits. Remeasurements of defined benefit plans are recognized immediately in other comprehensive income when incurred, while past service costs are recognized in profit or loss. (ii) Defined contribution plans Contributions to defined contribution retirement plans are recognized as expenses in the period when the employees render the related services.
Equity	(12) Equity (a) Ordinary shares Ordinary shares are classified as equity. Costs directly attributable to the issuance of ordinary shares (net of tax effects) are recognized as a deduction from equity. (b) Treasury stock When the Company acquires treasury stocks, the consideration paid, including any directly attributable costs (net of tax effects), is deducted from equity. In case of disposal of treasury stocks, the difference between the consideration received and the carrying amount of treasury stocks is recognized in equity.
Revenue	(13) Revenue The Group has adopted IFRS 15 “Revenue from Contracts with Customers” from the fiscal year ended March 31, 2019. Under IFRS 15, revenue is recognized based on the following five-steps. Step 1: Identify the contract with a customer Step 2: Identify the performance obligations in the contract Step 3: Determine the transaction price Step 4: Allocate the transaction price to the performance obligations in the contract Step 5: Recognize revenue when or as the Group satisfies a performance obligation Revenue generated from Steelmaking and Steel Fabrication segment and Chemicals and Materials segment consists primarily of revenue generated from sale of goods while revenue generated from Engineering and Construction segment and System Solutions segment primarily consists of services rendered under construction contracts. (a) Sale of goods The Group recognizes revenue from sale of goods when the customer obtains control of the goods and therefore a performance obligation is satisfied at a point in time whereby the Group no longer retains physical possession of goods upon shipment, the Group has the right to be paid from the customer, and when the legal title is transferred to the customer. With respect to revenue from rendering of service whose performance obligation is satisfied at a point in time, the Group recognizes revenue when the rendering of service is completed. Revenue is measured at the amount of consideration received or receivable less discounts and rebates. The consideration of the transaction is primarily collected within one year after the satisfaction of the performance obligation and it does not contain a significant financing component. (b) Construction contracts and built-to-order The Group recognizes revenue from construction contracts and built-to-order With respect to revenue from rendering of services whose performance obligation is satisfied over time, the Group recognizes revenue evenly throughout the duration of the service. The Group has adopted IFRS 15 “Revenue from Contracts with Customers” from the fiscal year ended March 31, 2019. In applying IFRS 15, the Group elected to apply the cumulative effect transition method where the cumulative effect of applying the Standard is recognized at the date of initial application. The adoption of the standard had no significant effect on each amount recognized in the consolidated financial statements.
Income taxes	(14) Income taxes Income taxes comprise of current taxes and deferred taxes, and are recognized in profit or loss, except for the items which are recognized directly in equity or other comprehensive income. Current taxes are measured at the amounts expected to be paid or recovered from the taxation authorities using the tax rates that have been enacted or substantively enacted at the end of the reporting period. Deferred tax assets and deferred tax liabilities are recognized based on future tax consequences attributable to temporary differences between the carrying amounts of assets or liabilities for accounting purposes and the tax bases of the assets or liabilities, carryforward of unused tax losses and tax credits. Deferred tax assets are recognized to the extent that it is probable that taxable profit will be available against which the deductible temporary differences, unused tax losses and unused tax credits can be utilized. Deferred tax assets are reviewed at the end of each reporting period and recognized only to the extent that it is probable that the tax benefits can be realized. However, deferred tax assets are not recognized if the initial recognition of an asset or liability in a transaction that is not a business combination affects neither accounting profit nor taxable profit at the time of the transaction. Deferred tax assets arising from deductible temporary differences associated with investments in subsidiaries, associates and interests in joint arrangements are recognized only to the extent of the following circumstances: • The temporary difference will reverse in the foreseeable future; and • Taxable profit will be available against which the temporary difference can be utilized. Deferred tax liabilities are recognized for all taxable temporary differences, except for the following circumstances: • On the initial recognition of goodwill; • On the initial recognition of an asset or liability in a transaction that is not a business combination affects neither accounting profit nor taxable profit at the time of the transaction; • Taxable temporary differences associated with investments in subsidiaries to the extent that the parent company is able to control the timing of the reversal of the temporary difference and it is probable that the temporary difference will not reverse in the foreseeable future. Deferred tax assets and deferred tax liabilities are offset when there is a legally enforceable right to offset current tax assets against current tax liabilities and in either of the following circumstances: • Income taxes are levied by the same taxation authority on the same taxable entity; or • Different taxable entities intend either to settle current tax assets and current tax liabilities on a net basis, or to realize the current tax assets and settle the current tax liabilities simultaneously.
Earnings per share	(15) Earnings per share Basic earnings per share is calculated by dividing the profit for the reporting period attributable to owners of the Company by the weighted average number of common stock outstanding during the period in which the number of treasury stock is excluded.

Significant Accounting Polici_3

Significant Accounting Policies (Tables)	12 Months Ended
	Mar. 31, 2019
Text block [abstract]
Summary of Estimated Useful Lives of Property, Plant and Equipment	The estimated useful lives of major property, plant and equipment are as follows: •  Buildings: Principally 31 years •  Machinery: Principally 14 years
Summary of Estimated Useful Lives of Intangible Assets	The estimated useful lives of major intangible assets with finite useful lives are as follows: •  Software: Principally 5 years •  Mining rights: Principally 25 years

Segment Information (Tables)

Segment Information (Tables)	12 Months Ended
	Mar. 31, 2019
Text block [abstract]
Summary of Segment Revenue, Segment Profit, Segment Assets and Liabilities and Other Items	(3) Information about segment revenue, segment profit, segment assets and liabilities and other items Year ended March 31, 2019 (Millions of Yen) Reportable segment Subtotal Adjustments Consolidated Steelmaking Engineering Chemicals System Revenue Revenue from external customers 5,408,633 321,346 243,014 204,952 6,177,947 — 6,177,947 Inter-segment revenue or transfers 45,902 35,360 4,052 62,550 147,867 (147,867 ) — Total 5,454,536 356,707 247,067 267,503 6,325,814 (147,867 ) 6,177,947 Segment profit 274,672 9,474 25,095 26,576 335,818 1,122 336,941 Other items Depreciation and amortization 398,702 2,605 6,644 4,872 412,825 (4,208 ) 408,616 Share of profit in investments accounted for using the equity method 76,337 801 1,339 (5 ) 78,473 7,938 86,411 Segment assets 7,404,841 289,083 194,622 231,994 8,120,542 (71,013 ) 8,049,528 Other items Investments accounted for using the equity method 672,853 6,313 23,629 309 703,105 90,041 793,146 Capital expenditure 431,775 3,021 8,855 2,542 446,194 (5,363 ) 440,830 Segment liabilities (Interest-bearing 2,365,587 5,937 7,075 2,631 2,381,231 (12,000 ) 2,369,231 Notes: 1. The adjustments of segment profit of 1,122 million yen include investment return of 8,237 million yen from the equity method associate Nippon Steel Kowa Real Estate Co., Ltd., and elimination of inter-segment revenue or transfers of (7,114) million yen. 2. The adjustments of segment liabilities include the elimination of the Steelmaking and Steel Fabrication segment’s borrowings from the System Solutions segment. Year ended March 31, 2018 (Millions of Yen) Reportable segment Subtotal Adjustments Total IFRS Consolidated Steelmaking Engineering Chemicals System Revenue Revenue from external customers 4,983,335 260,908 234,108 190,310 5,668,663 — 5,668,663 44,302 5,712,965 Inter-segment revenue or transfers 33,910 33,360 3,709 53,889 124,868 (124,868 ) — — — Total 5,017,245 294,268 237,817 244,200 5,793,531 (124,868 ) 5,668,663 44,302 5,712,965 Segment profit 245,708 9,110 17,399 23,292 295,510 2,030 297,541 (8,840 ) 288,700 Other items Finance income 4,983 180 38 146 5,348 (202 ) 5,146 2,498 7,644 Finance costs 20,080 44 172 11 20,309 (202 ) 20,106 4,477 24,584 Depreciation and amortization 330,393 2,489 7,329 4,646 344,859 (4,140 ) 340,719 25,845 366,565 Share of profit in investments accounted for using the equity method 116,408 378 148 (10 ) 116,925 5,750 122,675 (57,018 ) 65,657 Segment assets 7,003,681 247,696 184,988 223,601 7,659,967 (67,554 ) 7,592,413 163,721 7,756,134 Other items Investments accounted for using the equity method 950,887 4,393 24,843 17 980,142 83,614 1,063,757 (264,517 ) 799,239 Capital expenditure 390,623 6,301 8,497 7,638 413,061 (1,130 ) 411,930 11,497 423,428 Segment liabilities (Interest-bearing debt) 2,057,997 8,313 11,519 3,693 2,081,524 (12,527 ) 2,068,996 88,759 2,157,755 Notes: 1. The adjustments of segment profit of 2,030 million yen include investment return of 5,929 million yen from the equity method associate Nippon Steel Kowa Real Estate Co., Ltd., and elimination of inter-segment revenue or transfers of (3,899) million yen. 2. The adjustments of segment liabilities include the elimination of the Steelmaking and Steel Fabrication segment’s borrowings from the System Solutions segment. Year ended March 31, 2017 (Millions of Yen) Reportable segment Subtotal Adjustments Total IFRS Consolidated Steelmaking Engineering Chemicals System Revenue Revenue from external customers 4,016,670 234,861 203,115 178,242 4,632,890 — 4,632,890 63,937 4,696,828 Inter-segment 35,590 32,683 5,630 54,270 128,175 (128,175 ) — — — Total 4,052,261 267,545 208,746 232,512 4,761,065 (128,175 ) 4,632,890 63,937 4,696,828 Segment profit 138,017 6,838 6,304 22,113 173,274 1,256 174,531 (4,652 ) 169,878 Other items Finance income 5,566 124 36 133 5,860 (206 ) 5,654 668 6,322 Finance costs 17,831 118 233 28 18,212 (206 ) 18,006 3,579 21,586 Depreciation and amortization 294,008 2,653 8,227 4,174 309,064 (4,313 ) 304,751 26,161 330,912 Share of profit in investments accounted for using the equity method 70,723 655 920 21 72,320 6,859 79,180 (35,062 ) 44,118 Other items Capital expenditure 335,733 5,637 9,229 4,343 354,943 (3,905 ) 351,038 11,486 362,525 Notes: 1. The adjustments of segment profit of 1,256 million yen include investment return of 6,524 million yen from the equity method associate Nippon Steel Kowa Real Estate Co., Ltd., investment return of 629 million yen from the equity method associate SUMCO Corporation, and elimination of inter-segment revenue or transfers of (5,897) million yen. 2. The adjustments of segment liabilities include the elimination of the Steelmaking and Steel Fabrication segment’s borrowings from the System Solutions segment.
Summary of Geographical Areas	(4) Information about geographical areas (a) Revenue Year ended March 31, 2019 (Millions of Yen) Japan Overseas Asia Other Total 4,053,188 2,124,758 1,310,890 813,868 6,177,947 Year ended March 31, 2018 (Millions of Yen) Japan Overseas Asia Other Total 3,729,176 1,983,789 1,274,380 709,409 5,712,965 Year ended March 31, 2017 (Millions of Yen) Japan Overseas Asia Other Total 2,980,400 1,716,427 1,068,459 647,967 4,696,828 Revenue information is based on the geographical location of customers and classified by region. (b) Non-current assets As of March 31, 2019 (Millions of Yen) Japan Overseas Total 2,978,818 435,078 3,413,896 As of March 31, 2018 (Millions of Yen) Japan Overseas Total 2,854,097 418,238 3,272,335 Non-current assets are based on the location of the asset and do not include financial assets, deferred tax assets and assets for retirement benefits.
Summary of Revenue from Major Customers	(5) Revenue from major customers (Millions of Yen) Related segment Year ended Year ended Year ended Nippon Steel & Sumikin Bussan Corporation Steelmaking and Steel Fabrication 1,170,241 849,244 744,657 Sumitomo Corporation Steelmaking and Steel Fabrication 762,888 772,942 674,139 Metal One Corporation Steelmaking and Steel Fabrication 631,639 592,146 —

Business Combinations (Tables)

Business Combinations (Tables)	12 Months Ended
	Mar. 31, 2019
OvakoAB [member]
Statement [LineItems]
Details of Consideration Transferred	(b) Consideration transferred (Millions of Yen) Cash 51,767 Total consideration transferred 51,767
Summary of Fair Value the Identifiable Assets Acquired and Liabilities Assumed	(c) Fair value of the assets acquired and liabilities assumed and goodwill (Millions of Yen) Current assets 63,555 Non-current assets 53,302 Total assets 116,858 Current liabilities 70,691 Non-current liabilities 17,032 Total liabilities 87,724 Total identifiable net assets acquired 29,133 Total equity attributable to owners of the parent 29,133 Total consideration transferred 51,767 Goodwill 22,634
Summary of Net Cash used in the transaction	(d) Net cash used in the transaction (Millions of Yen) Cash consideration transferred 51,767 Cash and cash equivalents held by the acquiree at the acquisition date (5,961 ) Net cash used in the transaction 45,805
Sanyo Special Steel Co Ltd [member]
Statement [LineItems]
Summary of Revenue and Profit or Loss in Business Combination	(f) Revenue and profit or loss of the Group if the business combination had been completed at the beginning of the year (Unaudited) (Millions of Yen) Revenue 6,363,765 Profit before income taxes 259,145
Details of Consideration Transferred	(b) Consideration transferred (Millions of Yen) Cash 67,235 Fair value of equity interests held before the acquisition date 13,737 Total consideration transferred 80,972
Summary of Fair Value the Identifiable Assets Acquired and Liabilities Assumed	(c) Fair value of the assets acquired and liabilities assumed, non-controlling interests and bargain purchase gain The Company has not completed the fair value measurement of acquired assets and assumed liabilities, and accordingly the computation of non-controlling interests, bargain purchase gain and the purchase price allocations are on a provisional basis based on the most current information available. (Millions of Yen) Current assets 210,344 Non-current assets 75,075 Total assets 285,419 Current liabilities 61,789 Non-current liabilities 38,804 Total liabilities 100,593 Total identifiable net assets acquired 184,826 Non-controlling interests 90,274 Total equity attributable to owners of the parent 94,551 Total consideration transferred 80,972 Bargain purchase gain 13,578
Summary of Net Cash used in the transaction	(d) Net cash used in the transaction (Millions of Yen) Cash consideration transferred 67,235 Cash and cash equivalents held by the Sanyo at the acquisition date (79,196 ) Net cash provided in the transaction (11,961 )
Nisshin Steel Co Ltd [member]
Statement [LineItems]
Summary of Revenue and Profit or Loss in Business Combination	(f) Revenue and profit or loss of the Group if the business combination had been completed at the beginning of the year (Unaudited) (Millions of Yen) Revenue 5,222,392 Profit before income taxes 199,831
Details of Consideration Transferred	(b) Consideration transferred (Millions of Yen) Cash 75,972 Fair value of equity interests held before the date of acquisition 14,781 Total consideration transferred 90,753
Summary of Fair Value the Identifiable Assets Acquired and Liabilities Assumed	(c) Fair value of the assets acquired and liabilities assumed, non-controlling interests and goodwill (Millions of Yen) Current asset 246,040 Non-current assets 423,937 Total assets 669,978 Current liabilities 224,318 Non-current liabilities 259,936 Total liabilities 484,255 Total identifiable net assets acquired 185,722 Non-controlling interests 98,105 Total equity attributable to owners of the parent 87,616 Total consideration transferred 90,753 Goodwill 3,136
Summary of Net Cash used in the transaction	(d) Net cash used in the transaction (Millions of Yen) Cash consideration transferred 75,972 Cash and cash equivalents held by the Nisshin Steel at the acquisition date (23,079 ) Net cash used in the transaction 52,892

Cash and Cash Equivalents (Tabl

Cash and Cash Equivalents (Tables)	12 Months Ended
	Mar. 31, 2019
Text block [abstract]
Summary of Components of Cash and Cash Equivalents	The components of cash and cash equivalents are as follows: (Millions of Yen) As of As of As of Cash 159,636 138,702 119,793 Cash equivalents 3,540 4,166 4,135 Total 163,176 142,869 123,929

Trade and Other Receivables (Ta

Trade and Other Receivables (Tables)	12 Months Ended
	Mar. 31, 2019
Text block [abstract]
Summary of Components of Trade and Other Receivables	The components of trade and other receivables are as follows: (Millions of Yen) As of As of Notes and accounts receivable 842,573 730,805 Other 128,166 103,336 Allowance for doubtful receivables (2,407 ) (2,101 ) Total 968,333 832,040

Inventories (Tables)

Inventories (Tables)	12 Months Ended
	Mar. 31, 2019
Text block [abstract]
Summary of Inventories	The components of inventories are as follows: (Millions of Yen) As of As of Merchandise and finished goods 831,597 701,173 Work in progress 87,814 72,425 Raw materials and supplies 647,704 626,222 Total 1,567,116 1,399,821

Assets Pledged as Collateral (T

Assets Pledged as Collateral (Tables)	12 Months Ended
	Mar. 31, 2019
Text block [abstract]
Summary of Assets Pledged as Collateral and Secured debt	Assets pledged as collateral and secured debts are as follows: (Millions of Yen) Assets pledged as collateral As of As of Land 11,432 10,855 Buildings and structures 4,853 3,784 Machinery and vehicles 5,471 6,826 Other 13,475 4,907 Total 35,233 26,373 (Millions of Yen) Secured debts As of As of Short-term borrowings 3,635 970 Long-term borrowings (current portion is included) 6,242 5,383 Other 467 447 Total 10,345 6,801

Property, Plant and Equipment (

Property, Plant and Equipment (Tables)	12 Months Ended
	Mar. 31, 2019
Text block [abstract]
Property Plant and Equipment	Details of changes in the carrying amounts and acquisition costs, accumulated depreciation and accumulated impairment losses of property, plant and equipment are as follows: (Millions of Yen) Carrying amount Land Buildings Machinery Tools, Leased Construction Total As of March 31, 2017 654,349 815,580 1,266,968 48,413 46,783 260,106 3,092,202 Acquisitions and reclassified from construction in progress 1,831 71,336 277,566 24,810 10,401 16,255 402,200 Disposals and sales (2,858 ) (4,081 ) (2,637 ) (621 ) (246 ) (803 ) (11,249 ) Depreciation — (58,469 ) (257,642 ) (19,000 ) (9,486 ) — (344,599 ) Impairment losses (536 ) (5,955 ) (8,344 ) (564 ) — — (15,401 ) Effects of changes in foreign exchange rates (421 ) 868 10,997 189 (627 ) (10,300 ) 705 As of March 31, 2018 652,364 819,277 1,286,908 53,226 46,823 265,258 3,123,857 Acquisitions and reclassified from construction in progress 5,967 78,086 363,975 85,546 7,812 (72,830 ) 468,557 Acquisitions through business combinations 9,653 20,579 56,261 1,082 — 6,755 94,331 Disposals and sales (5,258 ) (3,660 ) (6,037 ) (4,570 ) (131 ) (129 ) (19,788 ) Depreciation — (58,817 ) (272,371 ) (46,659 ) (9,498 ) — (387,347 ) Effects of changes in foreign exchange rates (1,224 ) (190 ) (25,447 ) 719 (38 ) (6,758 ) (32,941 ) As of March 31, 2019 661,502 855,274 1,403,287 89,343 44,967 192,294 3,246,669 Depreciation of property, plant and equipment is mainly included in “Cost of sales” and “Selling, general and administrative expenses” in the consolidated statements of profit or loss. (Millions of Yen) Acquisition costs Land Buildings Machinery Tools, Leased Construction Total As of March 31, 2017 705,539 2,555,698 7,998,199 317,753 277,165 308,196 12,162,552 As of March 31, 2018 701,984 2,607,700 8,215,605 327,419 276,851 313,262 12,442,823 As of March 31, 2019 710,235 2,730,502 8,733,560 407,619 280,382 196,767 13,059,068 (Millions of Yen) Accumulated depreciation and Land Buildings Machinery Tools, Leased Construction Total As of March 31, 2017 51,189 1,740,118 6,731,230 269,340 230,382 48,089 9,070,350 As of March 31, 2018 49,620 1,788,422 6,928,697 274,193 230,027 48,003 9,318,966 As of March 31, 2019 48,733 1,875,228 7,330,272 318,276 235,414 4,473 9,812,398 The carrying amounts by type of leased assets are as follows: (Millions of Yen) Buildings and Machinery and Tools, furniture Total As of March 31, 2017 11,895 31,994 2,893 46,783 As of March 31, 2018 10,748 32,005 4,069 46,823 As of March 31, 2019 10,024 31,701 3,241 44,967

Goodwill and Intangible Assets

Goodwill and Intangible Assets (Tables)	12 Months Ended
	Mar. 31, 2019
Text block [abstract]
Summary of Carrying Amount of Goodwill and Intangible Assets	Details of changes in the carrying amounts and acquisition costs, accumulated amortization and accumulated impairment losses of goodwill and intangible assets are as follows: (Millions of Yen) Carrying amount Goodwill Software Mining rights Other Total As of March 31, 2017 44,563 47,165 44,630 5,878 142,237 Acquisitions — 18,698 — 2,528 21,227 Amortization — (18,443 ) (2,306 ) (1,215 ) (21,965 ) Impairment losses (2,472 ) (139 ) — (61 ) (2,673 ) Effects of changes in foreign exchange rates 173 (1,066 ) 1,898 (434 ) 569 As of March 31, 2018 42,263 46,214 44,221 6,695 139,395 Acquisitions — 19,470 — 807 20,278 Acquisitions through business combinations 22,634 1,891 — 16,333 40,859 Amortization — (17,868 ) (2,198 ) (1,202 ) (21,268 ) Impairment losses (10,963 ) — — — (10,963 ) Effect of changes in foreign exchange rates (1,131 ) (3,079 ) (4,884 ) (272 ) (9,367 ) As of March 31, 2019 52,803 46,629 37,139 22,362 158,934
Summary of Amortization of Intangible Assets	Amortization of intangible assets is included in “Cost of sales” and “Selling, general and administrative expenses” in the consolidated statements of profit or loss. (Millions of Yen) Acquisition costs Goodwill Software Mining rights Other Total As of March 31, 2017 44,563 87,236 63,304 12,131 207,236 As of March 31, 2018 44,736 97,253 66,107 17,203 225,301 As of March 31, 2019 66,238 115,358 58,617 30,875 271,090 Accumulated amortization and (Millions of Yen) Goodwill Software Mining rights Other Total As of March 31, 2017 — 40,071 18,674 6,252 64,999 As of March 31, 2018 2,472 51,039 21,885 10,507 85,905 As of March 31, 2019 13,435 68,729 21,478 8,512 112,155

Interests in Subsidiaries, As_2

Interests in Subsidiaries, Associates and Others (Tables)	12 Months Ended
	Mar. 31, 2019
Text block [abstract]
Summary of Major Subsidiaries of the Company	Major subsidiaries of the Company as of March 31, 2019 are as follows: Operating segment Name Address % of voting Steelmaking and Steel Fabrication Sanyo Special Steel Co., Ltd. Himeji-shi, Hyogo 51.5 % Steelmaking and Steel Fabrication Nisshin Co., Ltd. Chiyoda-ku, Tokyo 100.0 % Steelmaking and Steel Fabrication Nippon Steel & Sumikin Coated Sheet Corporation Chuo-ku, Tokyo 100.0 % Steelmaking and Steel Fabrication Osaka Steel Co., Ltd. Osaka-shi, Osaka 66.3 % Steelmaking and Steel Fabrication Nippon Steel & Sumikin Metal Products Co., Ltd. Koto-ku, Tokyo 100.0 % Steelmaking and Steel Fabrication Nippon Steel & Sumikin Pipe Co., Ltd. Chiyoda-ku, Tokyo 100.0 % Steelmaking and Steel Fabrication Kurosaki Harima Corporation Kitakyushu-shi, Fukuoka *47.0 % Steelmaking and Steel Fabrication Nippon Steel & Sumikin Texeng Co., Ltd. Chiyoda-ku, Tokyo 100.0 % Steelmaking and Steel Fabrication Nippon Steel & Sumikin Stainless Steel Corporation Chiyoda-ku, Tokyo 100.0 % Steelmaking and Steel Fabrication Nippon Steel & Sumikin Logistics Co., Ltd. Chuo-ku, Tokyo 100.0 % Steelmaking and Steel Fabrication Nippon Steel & Sumikin SG Wire Co., Ltd. Chiyoda-ku, Tokyo 100.0 % Steelmaking and Steel Fabrication Geostr Corporation Bunkyo-ku, Tokyo *42.3 % Steelmaking and Steel Fabrication Nippon Steel & Sumikin Welding Co., Ltd. Koto-ku, Tokyo 100.0 % Steelmaking and Steel Fabrication Nippon Steel & Sumikin Drum Co., Ltd. Koto-ku, Tokyo 100.0 % Steelmaking and Steel Fabrication Nippon Steel & Sumikin Blast Furnace Slag Cement Co., Ltd. Kitakyushu-shi, Fukuoka 100.0 % Steelmaking and Steel Fabrication Nippon Steel & Sumikin Cement Co., Ltd. Muroran-shi, Hokkaido 85.0 % Steelmaking and Steel Fabrication Nippon Steel & Sumikin Finance Co., Ltd. Chiyoda-ku, Tokyo 100.0 % Steelmaking and Steel Fabrication Nippon Steel & Sumikin Stainless Steel Pipe Co., Ltd. Koga-shi, Ibaraki 100.0 % Steelmaking and Steel Fabrication Nippon Steel & Sumikin Steel Wire Co., Ltd. Seki-shi, Gifu 51.0 % Steelmaking and Steel Fabrication Nippon Steel & Sumikin Eco-Tech Corporation Chuo-ku, Tokyo 85.1 % Steelmaking and Steel Fabrication Nippon Steel & Sumikin Bolten Corporation Osaka-shi, Osaka 85.0 % Steelmaking and Steel Fabrication Nippon Steel & SumikinShapes Corporation Wakayama-shi, Wakayama 100.0 % Steelmaking and Steel Fabrication Nippon Steel & Sumikin Tubos do Brasil Ltda. State of Rio de Janeiro, Brazil 100.0 % Steelmaking and Steel Fabrication NS-Siam United Steel Co., Ltd. Rayong Province, Thailand 80.2 % Steelmaking and Steel Fabrication National Pipe Company Limited Eastern Province, Saudi Arabia 51.0 % Steelmaking and Steel Fabrication Standard Steel, LLC Pennsylvania State, United States of America 100.0 % Steelmaking and Steel Fabrication Nippon Steel & Sumitomo Metal U.S.A., Inc. New York State, United States of America 100.0 % Steelmaking and Steel Fabrication PT Pelat Timah Nusantara Tbk. Jakarta City, Indonesia *35.0 % Steelmaking and Steel Fabrication Nippon Steel & Sumitomo Metal (Thailand) Co., Ltd. Bangkok Metropolis, Thailand 100.0 % Steelmaking and Steel Fabrication Nippon Steel & Sumitomo Metal Australia Pty. Limited New South Wales State, Australia 100.0 % Steelmaking and Steel Fabrication Nippon Steel & Sumikin Steel Processing (Thailand) Co., Ltd. Rayong Province, Thailand 66.5 % Steelmaking and Steel Fabrication Ovako AB Stockholm, Sweden 100.0 % Engineering and Construction Nippon Steel & Sumikin Engineering Co., Ltd. Shinagawa-ku, Tokyo 100.0 % Chemicals & Materials Nippon Steel Chemical & Material Co., Ltd. Chiyoda-ku, Tokyo 100.0 % System Solutions NS Solutions Corporation Chuo-ku, Tokyo 63.4 % * Although the Group holds less than 50% of the voting rights of Geostr Corporation, PT Pelat Timah Nusantara Tbk. and Kurosaki Harima Corporation, it includes the entities in consolidated subsidiaries because it substantially controls the entities.
Summary of Investments in Associates	Carrying amount of investments in associates is as follows: (Millions of Yen) As of As of Carrying amount of investments in associates 636,216 654,214 Share of net profit or loss and other comprehensive income of associates is as follows: (Millions of Yen) Year Ended Year Ended Year Ended Net profit or loss 49,436 38,199 29,622 Other comprehensive income (18,610 ) (270 ) 11,379 Total 30,826 37,929 41,002
Summary of Investments in Joint Ventures	Carrying amount of investments in joint ventures is as follows: (Millions of Yen) As of As of Carrying amount of investments in joint ventures 156,930 145,025 Share of net profit or loss and other comprehensive income of joint ventures is as follows: (Millions of Yen) Year Ended Year Ended Year Ended Net profit or loss 36,975 27,458 14,495 Other comprehensive income (6,030 ) 2,793 (1,108 ) Total 30,944 30,251 13,386

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Mar. 31, 2019
Text block [abstract]
Components of Deferred Tax Assets and Deferred Tax Liabilities	(a) The components of deferred tax assets and deferred tax liabilities are as follows: (Millions of Yen) As of As of Deferred tax assets Accrued bonus 28,189 26,453 Defined benefit liabilities 66,924 48,011 Impairment losses on non-financial assets 17,888 11,637 Property, plant and equipment 21,552 19,482 Unused tax losses 39,280 29,330 Elimination of unrealized gains on property, plant and equipment and others 31,553 29,681 Accrued expenses for demolition and removal of fixed assets 15,024 13,807 Other 48,820 39,367 Total deferred tax assets 269,234 217,772 Deferred tax liabilities Equity securities (108,609 ) (151,451 ) Defined benefit assets (25,167 ) (33,357 ) Undistributed earnings (31,570 ) (30,904 ) Special tax purpose reserves (43,782 ) (62,466 ) Total deferred tax liabilities (209,130 ) (278,179 ) Net deferred tax assets (liabilities) 60,104 (60,407 )
Summary of Changes in Deferred Tax Assets and Liabilities	(b) The changes in net deferred tax assets and liabilities are as follows: (Millions of Yen) Year Ended Year Ended Balance at beginning of the year (60,407 ) (38,993 ) Recognized in profit or loss 88,108 19,575 Recognized in other comprehensive income 37,761 (41,003 ) Effect of changes in consolidation scope (5,268 ) 14 Balance at end of the year 60,104 (60,407 )
Details of Deductible Temporary Differences and Unused Tax Losses	(c) Deductible temporary differences and unused tax losses for which no deferred tax assets are recognized are as follows: (Millions of Yen) As of As of Carryforward of unused tax losses 51,390 87,225 Deductible temporary differences 111,242 131,854 Total 162,633 219,080
Summary of Components of Unused Tax Losses	(d) The components by expiry date of unused tax losses for which no deferred tax assets are recognized are as follows: (Millions of Yen) As of As of Within 1 year 3,009 30,935 Over 2 years but less than 3 years 5,209 7,774 Over 3 years but less than 4 years 10,640 11,426 Over 4 years but less than 5 years 1,247 17,003 Over 5 years 31,283 20,085 Total 51,390 87,225
Details of Income Tax Expense	(a) Details of income tax expense are as follows: (Millions of Yen) Year Ended Year Ended Year Ended Current taxes 79,209 79,124 49,526 Deferred taxes (88,018 ) (19,575 ) (9,229 ) Total (8,809 ) 59,549 40,297
Details of Differences Between the Statutory Income Tax and Average Effective Tax Rate	(b) Differences between the statutory income tax rate and the Group’s average effective tax rate consist of the following: Year Ended Year Ended Year Ended Statutory tax rate 30.6 % 30.9 % 30.9 % Share of profit in investments accounted for using the equity method (7.3 ) (4.8 ) (4.5 ) Effects of expense not deductible for tax purposes 0.9 0.9 1.1 Effects of income not taxable for tax purposes (0.6 ) (0.6 ) (1.0 ) Effects of differences in statutory tax rates applied to companies in Japan and foreign companies (1.8 ) (2.3 ) (2.0 ) Effects of changes in unrecognized deferred tax assets (24.0 ) (4.0 ) (8.1 ) Other (1.4 ) 1.9 4.3 Average effective tax rate (3.5 ) 21.9 20.7

Trade and Other Payables (Table

Trade and Other Payables (Tables)	12 Months Ended
	Mar. 31, 2019
Text block [abstract]
Summary of Components of Trade and Other Payables	The components of trade and other payables are as follows: (Millions of Yen) As of As of Notes and trade accounts payable 821,009 782,605 Other payables 524,167 474,903 Other 266,226 323,087 Total 1,611,403 1,580,597

Bonds, Borrowings and Lease L_2

Bonds, Borrowings and Lease Liabilities (Tables)	12 Months Ended
	Mar. 31, 2019
Statement [LineItems]
Schedule of Details of Bonds	(2) Details of bonds (Millions of Yen) Type Issue date As of As of Maturity date Bonds issued by NSC Japanese Yen Corporate Bonds Maturity 2019 February 15, 1999 — 696 February 15, 2019 The 58 th September 2, 2008 — 30,000 June 20, 2018 The 59 th September 2, 2008 10,000 10,000 June 20, 2028 The 61 st December 2, 2008 — 15,000 September 20, 2018 The 63 rd June 9, 2009 20,000 20,000 June 20, 2019 The 64 th April 20, 2010 20,000 20,000 March 19, 2020 The 65 th August 31, 2010 15,000 15,000 June 19, 2020 The 67 th May 24, 2011 30,000 30,000 March 19, 2021 The 65 th May 31, 2011 — 10,000 May 31, 2018 The 68 th October 20, 2011 15,000 15,000 September 17, 2021 The 68 th October 20, 2011 — 10,000 October 19, 2018 The 70 th April 20, 2012 10,000 10,000 April 19, 2019 The 69 th July 20, 2012 10,000 10,000 June 20, 2019 The 70 th July 20, 2012 20,000 20,000 June 20, 2022 The 1 st September 26, 2016 10,000 10,000 September 18, 2026 The 2 nd September 26, 2016 10,000 10,000 September 19, 2031 The 3 rd May 25, 2017 10,000 10,000 May 20, 2024 The 4 th May 25, 2017 10,000 10,000 May 20, 2027 The 5 th December 8, 2017 10,000 10,000 December 20, 2024 The 6 th December 8, 2017 10,000 10,000 December 20, 2027 The 7 th June 12, 2018 20,000 — June 20, 2023 The 8 th June 12, 2018 20,000 — June 20, 2025 The 9 th June 12, 2018 20,000 — June 20, 2028 Bonds issued by Nisshin Steel The 19 th June 2, 2008 — 10,000 June 1, 2018 The 23 rd March 10, 2014 — 10,000 March 8, 2019 Bonds issued by Sanyo Special Steel The 2nd Issue of Unsecured Corporate Bonds December 7, 2017 10,000 — December 6, 2024 Total 280,000 295,696
Schedule of Reconciliation of Changes in Liabilities Arising from Financing Activities	The table below presents a reconciliation of main changes in liabilities arising from financing activities. (Millions of Yen) Short-term Commercial Long-term Bonds Lease Total As of March 31, 2017 142,769 31,854 1,595,610 396,005 48,688 2,214,928 Cash flows from financing activities (7,114 ) 57,140 2,672 (100,000 ) (12,377 ) (59,677 ) Effects of changes in consolidation scope 1,331 — 1,435 — (7 ) 2,759 Effects of changes in foreign exchange rates 276 4 (10,865 ) — 196 (10,387 ) Other 60 — (2,886 ) (309 ) 13,267 10,132 As of March 31, 2018 137,323 89,000 1,585,966 295,696 49,768 2,157,755 Cash flows from financing activities 44,401 23,000 102,850 (25,700 ) (9,792 ) 134,760 Effects of changes in consolidation scope 35,073 8,000 20,872 10,000 (65 ) 73,880 Effects of changes in foreign exchange rates (1,220 ) — (2,013 ) — (43 ) (3,277 ) Other (184 ) — (593 ) 3 6,886 6,112 As of March 31, 2019 215,393 120,000 1,707,083 280,000 46,754 2,369,231
Bonds, borrowings and lease liabilities [member]
Statement [LineItems]
Schedule of Details of Bonds	Details of bonds, borrowings and lease liabilities are as follows: (Millions of Yen) As of Average As of Average Maturity date Short-term borrowings 215,393 1.2 137,323 1.0 — Current portion of long-term borrowings repayable within one year 111,177 1.0 184,809 1.0 — Current portion of bonds repayable within one year 60,000 1.4 85,700 1.5 — Current portion of lease liabilities repayable within one year 8,783 0.8 8,550 0.8 — Commercial papers 120,000 (0.0 ) 89,000 (0.0 ) — Long-term borrowings 1,595,905 0.8 1,401,156 0.8 July 19, 2075 Bonds 220,000 0.7 209,996 1.0 September 19, 2031 Lease liabilities 37,970 0.8 41,218 0.8 March 31, 2076 Total 2,369,231 2,157,755

Leases (Tables)

Leases (Tables)	12 Months Ended
	Mar. 31, 2019
Text block [abstract]
Summary of Future Minimum Payments under Finance Lease Contracts	Future minimum lease payments under finance lease contracts are as follows: (Millions of Yen) Year ended Year ended Within 1year 8,783 8,550 Over 1 but less than 5 years 21,034 22,582 Over 5 years 16,936 18,635 Total 46,754 49,768
Summary of Future Minimum Payments under Non-Cancellable Operating Lease Contracts	The future minimum lease payments under non-cancellable operating lease contracts are as follows: (Millions of Yen) Year ended Year ended Within 1 year 11,371 9,965 Over 1 but less than 5 years 29,434 31,624 Over 5 years 4,994 6,638 Total 45,800 48,228
Summary of Future Minimum Payments Expected to be Received under Non-Cancellable Operating Lease Contracts	The future lease payments expected to be received under non-cancellable operating lease contracts are as follows: (Millions of Yen) Year ended Year ended Within 1 year 2,314 1,906 Over 1 but less than 5 years 8,326 6,549 Over 5 years 21,712 7,654 Total 32,353 16,110

Employee Benefits (Tables)

Employee Benefits (Tables)	12 Months Ended
	Mar. 31, 2019
Text block [abstract]
Changes in Present Value of Defined Benefit Obligations and Fair Value of Plan Assets	The changes in the present value of the defined benefit obligations for the Group are as follows: (Millions of Yen) Year ended Year ended Balance at beginning of the year 619,280 650,749 Current service cost 34,137 34,168 Interest cost 2,610 2,591 Actuarial gains and losses 6,183 296 Past service cost (54 ) (5,700 ) Benefits paid (48,542 ) (55,624 ) Other 17,137 (7,199 ) Balance at end of the year 630,754 619,280 The weighted average duration of the defined benefit obligations for the years ended March 31, 2019 and 2018 is 11.9 years and 11.5 years, respectively. (3) Reconciliation of the fair value of the plan assets The changes in the fair value of the plan assets for the Group are as follows: (Millions of Yen) Year ended Year ended Balance at beginning of the year 554,671 545,072 Interest income 2,986 2,788 Return on plan assets, excluding interest income (457 ) 29,550 Employer contributions 13,903 13,765 Benefits paid (29,682 ) (34,637 ) Other (15,174 ) (1,866 ) Balance at end of the year 526,246 554,671
Components of Fair Value of Plan Assets by Asset Category	The components of the fair value of plan assets by asset category are as follows: (Millions of Yen) As of As of With quoted With no With quoted With no Bonds 80,469 — 83,441 — Equity investments 208,456 — 249,400 — Cash and cash equivalents 43,857 — 32,799 — General accounts at life insurance company — 126,547 — 123,396 Other — 66,915 — 65,633 Total 332,783 193,463 365,641 189,030
Significant Actuarial Assumptions Used to Determine Present Value of Defined Benefit Obligations	The significant actuarial assumptions used to determine the present value of defined benefit obligations for the Company are as follows: As of As of Discount rate 0.3 % 0.3 %
Effects on Defined Benefit Obligations of Increase in Discount Rates	The effects on defined benefit obligations of increase in the discount rates are as follows: (Millions of Yen) Year ended Year ended Effects of incremental increase in discount rate by 0.5% 33,151 million yen 32,049 million yen

Equity and Other Equity Items (

Equity and Other Equity Items (Tables)	12 Months Ended
	Mar. 31, 2019
Text block [abstract]
Total Number of Shares Authorized to be Issued and Shares Outstanding	The total number of shares authorized to be issued and shares outstanding are as follows: Number of shares Number of shares As of March 31, 2017 2,000,000 950,321 Changes — — As of March 31, 2018 2,000,000 950,321 Changes — — As of March 31, 2019 2,000,000 950,321
Total Number of Treasury Stock Held	The total number of treasury stock held by the Group is as follows: Number of shares As of March 31, 2017 67,674 Changes 36 As of March 31, 2018 67,710 Changes (37,912 ) As of March 31, 2019 29,797

Dividends (Tables)

Dividends (Tables)	12 Months Ended
	Mar. 31, 2019
Text block [abstract]
Dividends Paid	The dividends paid by the Company are as follows: Year ended March 31, 2019 (1) Dividends paid Date of resolution Class of share Total amount of Dividends per Record date Effective date Shareholders’ meeting held on June 26, 2018 Ordinary shares 35,355 40 March 31, 2018 June 27, 2018 Board of directors meeting held on November 2, 2018 Ordinary shares 35,355 40 September 30, 2018 December 3, 2018 (2) Dividends that belong to the current consolidated reporting year but become effective in the subsequent consolidated reporting year Date of resolution Class of share Source of Total amount of Dividends per Record date Effective date Shareholders’ meeting held on June 25, 2019 Ordinary shares Retained 36,880 40 March 31, 2019 June 26, 2019 Year ended March 31, 2018 (1) Dividends paid Date of resolution Class of share Total amount of Dividends per Record date Effective date Shareholders’ meeting held on June 27, 2017 Ordinary shares 39,776 45 March 31, 2017 June 28, 2017 Board of directors meeting held on October 27, 2017 Ordinary shares 26,517 30 September 30, 2017 November 30, 2017 (2) Dividends that belong to the current consolidated reporting year but become effective in the subsequent consolidated reporting year Date of resolution Class of share Source of Total amount of Dividends per Record date Effective date Shareholders’ meeting held on June 26, 2018 Ordinary shares Retained 35,355 40 March 31, 2018 June 27, 2018 Year ended March 31, 2017 (3) Dividends paid Date of resolution Class of share Total amount of Dividends per Record date Effective date Shareholders’ meeting held on June 24, 2016 Ordinary shares 13,554 15 March 31, 2016 June 27, 2016 (4) Dividends that belong to the current consolidated reporting year but become effective in the subsequent consolidated reporting year Date of resolution Class of share Source of Total amount of Dividends per Record date Effective date Shareholders’ meeting held on June 27, 2017 Ordinary shares Retained 39,776 45 March 31, 2017 June 28, 2017

Revenue (Tables)

Revenue (Tables)	12 Months Ended
	Mar. 31, 2019
Text block [abstract]
Disaggregation of Revenue from Contracts with Customers and its Relationship with Segment Revenue	Disaggregation of revenue from contracts with customers and its relationship with segment revenue are as follows. Year ended March 31, 2019 (Millions of Yen) Steelmaking Engineering Chemicals System Consolidated Japan 3,431,461 264,674 155,184 201,868 4,053,188 Asia 1,194,440 34,746 78,872 2,831 1,310,890 Middle East 113,180 2 319 — 113,502 Europe 142,335 20,645 4,426 66 167,473 North America 279,575 997 4,055 151 284,779 Central and South America 188,473 279 156 34 188,944 Africa 46,202 — 0 — 46,202 Pacific 12,963 — 0 — 12,964 Total 5,408,633 321,346 243,014 204,952 6,177,947
Contract Balances	Contract balances (Millions of Yen) At beginning of the year As of Receivables 685,761 774,803 Contract assets 45,044 67,769 Contract liabilities 22,936 28,488
Transaction Price Allocated to Remaining Performance Obligation	Transaction price allocated to the remaining performance obligation (Millions of Yen) As of March 31, 2019 Engineering and System Solutions Within 1 year 259,610 184,782 74,828 Over 1 year 202,262 170,569 31,693 Total 461,872 355,351 106,521

Selling, General and Administ_2

Selling, General and Administration Expenses (Tables)	12 Months Ended
	Mar. 31, 2019
Text block [abstract]
Components of Selling, General and Administrative Expenses	The components of selling, general and administrative expenses are as follows: (Millions of Yen) Year ended Year ended Year ended Transportation and storage 161,091 141,873 112,637 Salaries and bonuses 141,390 137,687 122,184 Retirement benefit costs 8,713 7,336 5,897 Research and development costs 58,621 61,019 54,912 Depreciation and amortization 8,693 10,064 7,138 Other 189,901 175,804 163,584 Total 568,409 533,787 466,351

Research and Development Costs

Research and Development Costs (Tables)	12 Months Ended
	Mar. 31, 2019
Text block [abstract]
Total Amounts of Research and Development Costs	The total amounts of research and development costs included in “Cost of sales” and “Selling, general and administrative expenses” are as follows: (Millions of Yen) Year ended Year ended Year ended Research and development costs 72,043 74,071 70,100

Other Operating Income and Ot_2

Other Operating Income and Other Operating Expenses (Tables)	12 Months Ended
	Mar. 31, 2019
Text block [abstract]
Other Operating Income	Other operating income (Millions of Yen) Year ended Year ended Year ended Dividends received 20,156 17,832 15,005 Foreign exchanges gains (net) 6,152 — — Other 76,296 73,689 47,102 Total 102,606 91,521 62,108
Other Operating Expenses	Other operating expenses (Millions of Yen) Year ended Year ended Year ended Foreign exchanges losses (net) — 3,976 9,310 Impairment losses — 18,075 — Losses on disposal of fixed assets 27,665 30,540 32,322 Other 42,455 46,181 39,539 Total 70,120 98,773 81,171

Finance Income and Finance Co_2

Finance Income and Finance Costs (Tables)	12 Months Ended
	Mar. 31, 2019
Text block [abstract]
Disclosure Components of Finance Income	Finance income (Millions of Yen) Year ended Year ended Year ended Interest income 6,028 5,710 6,241 Other 76 1,933 81 Total 6,104 7,644 6,322
Disclosure Components of Finance costs	Finance costs (Millions of Yen) Year ended Year ended Year ended Interest expense 19,133 21,339 19,292 Other 3,311 3,245 2,293 Total 22,445 24,584 21,586

Impairment of Assets (Tables)

Impairment of Assets (Tables)	12 Months Ended
	Mar. 31, 2019
Text block [abstract]
Summary of Impairment Losses	Impairment losses Year ended March 31, 2019 (Millions of Yen) Steelmaking and Engineering and Chemicals and System Solutions Adjustments Total 11,909 4,972 — — — 16,882 Year ended March 31, 2018 (Millions of Yen) Steelmaking and Engineering and Chemicals and System Solutions Adjustments Total 9,932 2,472 3,334 2,570 (234 ) 18,075
Summay of Carrying Amount of Goodwill by Segment	Impairment test of goodwill The breakdown of the carrying amount of goodwill by segment is as follows: (Millions of Yen) Operating segment As of As of Steelmaking and Steel Fabrication 44,477 28,596 Engineering and Construction 3,300 8,641 Chemicals and Materials — — System Solutions 5,025 5,025 Total 52,803 42,263

Other Comprehensive Income (Tab

Other Comprehensive Income (Tables)	12 Months Ended
	Mar. 31, 2019
Text block [abstract]
Components of Other Comprehensive Income	The components of other comprehensive income are as follows: Year ended March 31, 2019 (Millions of Yen) Incurred during Reclassification Before tax Tax effect After tax Items that cannot be reclassified to profit or loss Changes in fair value of financial assets measured at fair value through other comprehensive income (138,361 ) — (138,361 ) 33,804 (104,557 ) Remeasurements of defined benefit assets (6,641 ) — (6,641 ) 3,109 (3,531 ) Share of other comprehensive income of investments accounted for using the equity method (2,953 ) — (2,953 ) — (2,953 ) Subtotal (147,956 ) — (147,956 ) 36,913 (111,042 ) Items that might be reclassified to profit or loss Changes in fair value of cash flow hedges 6,155 (4,234 ) 1,921 (398 ) 1,522 Foreign exchange differences on translation of foreign operations (42,391 ) (111 ) (42,502 ) 1,246 (41,256 ) Share of other comprehensive income of investments accounted for using the equity method (21,750 ) 62 (21,687 ) — (21,687 ) Subtotal (57,985 ) (4,283 ) (62,269 ) 847 (61,421 ) Total (205,942 ) (4,283 ) (210,225 ) 37,761 (172,464 ) Year ended March 31, 2018 (Millions of Yen) Incurred during Reclassification Before tax Tax effect After tax Items that cannot be reclassified to profit or loss Changes in fair value of financial assets measured at fair value through other comprehensive income 94,274 — 94,274 (29,051 ) 65,222 Remeasurements of defined benefit assets 29,253 — 29,253 (9,831 ) 19,422 Share of other comprehensive income of investments accounted for using the equity method 5,125 — 5,125 — 5,125 Subtotal 128,653 — 128,653 (38,883 ) 89,770 Items that might be reclassified to profit or loss Changes in fair value of cash flow hedges (2,351 ) 4,678 2,326 (538 ) 1,788 Foreign exchange differences on translation of foreign operations 12,390 (215 ) 12,174 (1,582 ) 10,592 Share of other comprehensive income of investments accounted for using the equity method (2,488 ) (113 ) (2,602 ) — (2,602 ) Subtotal 7,550 4,349 11,899 (2,120 ) 9,778 Total 136,203 4,349 140,552 (41,003 ) 99,548 Year ended March 31, 2017 (Millions of Yen) Incurred during Reclassification Before tax Tax effect After tax Items that cannot be reclassified to profit or loss Changes in fair value of financial assets measured at fair value through other comprehensive income 119,533 — 119,533 (33,263 ) 86,269 Remeasurements of defined benefit assets 33,791 — 33,791 (9,727 ) 24,063 Share of other comprehensive income of investments accounted for using the equity method 406 — 406 — 406 Subtotal 153,732 — 153,732 (42,991 ) 110,740 Items that might be reclassified to profit or loss Changes in fair value of cash flow hedges 5,404 8,533 13,937 (4,485 ) 9,452 Foreign exchange differences on translation of foreign operations (28,332 ) 2,551 (25,781 ) 702 (25,079 ) Share of other comprehensive income of investments accounted for using the equity method 8,008 1,854 9,863 — 9,863 Subtotal (14,919 ) 12,939 (1,980 ) (3,782 ) (5,763 ) Total 138,812 12,939 151,751 (46,774 ) 104,977

Earnings per Share (Tables)

Earnings per Share (Tables)	12 Months Ended
	Mar. 31, 2019
Text block [abstract]
Summary of Profit Attributable to Common Shares of the Parent	Profit for the year attributable to common shares of the parent is as follows: (Millions of Yen) Year ended Year ended Year ended Profit for the year attributable to owners of the parent 251,169 180,832 137,246 Profit for the year not attributable to ordinary equity holders of the parent — — — Profit for the year used to calculate basic earnings per share 251,169 180,832 137,246
Summary of Weighted Average Number of Ordinary Shares Outstanding	The weighted average number of ordinary shares outstanding is as follows: (Shares) Year ended Year ended Year ended Weighted average number of ordinary shares outstanding 891,387,729 882,629,157 884,959,677

Financial Instruments (Tables)

Financial Instruments (Tables)	12 Months Ended
	Mar. 31, 2019
Statement [LineItems]
Schedule of Key Management Indicators to Achieve Medium and Long-term Profit Growth and Stability	The Group identifies Return on Equity (“ROE”) and Debt Equity Ratio (“D/E ratio”) as key management indicators to achieve medium and long-term profit growth and stability of the financial base. ROE is calculated by dividing profit for the year attributable to owners of the parent by the equity attributable to owners of the parent. D/E ratio is calculated by dividing interest-bearing debts by the equity attributable to owners of the parent. As of As of ROE (%) 7.9 6.0 D/E Ratio (times) 0.73 0.69
Schedule of Carrying Amounts of Financial Instruments by Classification	The carrying amounts of financial instruments by classification as of March 31, 2019 and 2018 are as follows: As of March 31, 2019 Financial assets (Millions of Yen) Carrying amount Amortized cost Fair value Total FVPL FVOCI Current assets Cash and cash equivalents 163,176 — — 163,176 Trade and other receivables 900,563 — — 900,563 Other financial assets 12,844 590 3,480 16,915 Derivatives — 590 3,480 4,071 Debt instruments 12,844 — — 12,844 Non-current assets Other financial assets 84,211 — 728,456 812,668 Equity instruments — — 718,470 718,470 Derivatives — — 9,985 9,985 Debt instruments 84,211 — — 84,211 Financial liabilities (Millions of Yen) Carrying amount Amortized cost Fair value Total FVPL FVOCI Current liabilities Trade and other payables 1,611,403 — — 1,611,403 Bonds and borrowings 506,571 — — 506,571 Other financial liabilities Derivatives — 258 758 1,017 Non-current liabilities Bonds and borrowings 1,815,905 — — 1,815,905 Other financial liabilities Derivatives — — 6,501 6,501 Other non-current liabilities 142,149 — — 142,149 As of March 31, 2018 Financial assets (Millions of Yen) Carrying amount Amortized cost Fair value Total FVPL FVOCI Current assets Cash and cash equivalents 142,869 — — 142,869 Trade and other receivables 832,040 — — 832,040 Other financial assets 12,351 61 6,765 19,178 Derivatives — 61 6,765 6,827 Debt instruments 12,351 — — 12,351 Non-current assets Other financial assets 74,538 — 933,088 1,007,627 Equity instruments — — 926,465 926,465 Derivatives — — 6,623 6,623 Debt instruments 74,538 — — 74,538 Financial liabilities (Millions of Yen) Carrying amount Amortized cost Fair value Total FVPL FVOCI Current liabilities Trade and other payables 1,580,597 — — 1,580,597 Bonds and borrowings 496,833 — — 496,833 Other financial liabilities Derivatives — 329 344 674 Non-current liabilities Bonds and borrowings 1,611,153 — — 1,611,153 Other financial liabilities Derivatives — — 6,572 6,572 Other non-current liabilities 120,156 — — 120,156
Schedule of Financial Instruments Measured at Fair Value	The tables below represent the financial instruments measured at fair value on a recurring basis by level as of March 31, 2019 and March 31, 2018. As of March 31, 2019 Financial assets measured at fair value (Millions of Yen) Level 1 Level 2 Level 3 Total FVPL Other financial assets Derivatives — 590 — 590 FVOCI Other financial assets Equity instruments 638,768 — 79,702 718,470 Derivatives — 13,466 — 13,466 Financial liabilities measured at fair value (Millions of Yen) Level 1 Level 2 Level 3 Total FVPL Other financial liabilities Derivatives — 258 — 258 FVOCI Other financial liabilities Derivatives — 7,260 — 7,260 As of March 31, 2018 Financial assets measured at fair value (Millions of Yen) Level 1 Level 2 Level 3 Total FVPL Other financial assets Derivatives — 61 — 61 FVOCI Other financial assets Equity instruments 847,645 — 78,819 926,465 Derivatives — 13,388 — 13,388 Financial liabilities measured at fair value (Millions of Yen) Level 1 Level 2 Level 3 Total FVPL Other financial liabilities Derivatives — 329 — 329 FVOCI Other financial liabilities Derivatives — 6,917 — 6,917
Schedule of Changes in Equity Instruments Measured at Level 3	The changes of equity instruments measured at Level 3 are as follows: (Millions of Yen) Year ended Year ended Balance at beginning of the year 78,819 83,237 Net changes in fair value 1,122 1,197 Acquisitions 116 54 Sale / settlements (641 ) (2,106 ) Other 286 (3,562 ) Balance at end of the year 79,702 78,819
Fair Value Of Significant Equity Instruments Measured at FVOCI	Fair value of significant equity instruments measured at FVOCI by name As of Amount Toyota Motor Corporation 80,312 POSCO 70,952 Suzuki Motor Corporation 38,006 Recruit Holdings 37,110 Central Japan Railway Company 30,633 As of Amount POSCO 96,996 Toyota Motor Corporation 79,778 SUMCO Corporation 64,783 Suzuki Motor Corporation 44,462 Vallourec S.A. 37,466
Derecognition of Financial Assets Measured at Fair Value Through Other Comprehensive Income	The Group derecognizes certain financial assets that are measured at fair value through other comprehensive income as a result of disposals through sale occurring as a result of review of business relationships. (Millions of Yen) Year ended Year ended Fair value at the time of derecognition 83,726 37,532 Cumulative gains or losses on disposal (net of tax) 14,679 6,542
Summary of Dividends Recognized for the Equity Investments Measured at FVOCI	Dividends recognized for the equity investments measured at FVOCI during the reporting period (Millions of Yen) Year ended Year ended Investment derecognized in the reporting period 2,168 865 Investment held at the end of reporting period 17,988 16,967 Total 20,156 17,832
Fair Value of Financial Assets and Liabilities Measured at Amortized Cost	The fair value of financial assets and financial liabilities measured at amortized cost is as follows: (Millions of Yen) As of March 31, 2019 Carrying Fair value Level 1 Level 2 Level 3 Financial assets (Current) Other financial assets Debt instruments 12,844 9,498 0 3,345 Financial assets (Non-current) Other financial assets Debt instruments 84,211 11 7,512 76,699 Financial liabilities (Current) Bonds and borrowings 506,571 60,386 — 446,571 Financial liabilities (Non-current) Bonds and borrowings 1,815,905 224,669 — 1,618,043 (Millions of Yen) As of March 31, 2018 Carrying Fair value Level 1 Level 2 Level 3 Financial assets (Current) Other financial assets Debt instruments 12,351 1,233 3,103 8,018 Financial assets (Non-current) Other financial assets Debt instruments 74,538 23 5,497 69,015 Financial liabilities (Current) Bonds and borrowings 496,833 86,080 — 411,133 Financial liabilities (Non-current) Bonds and borrowings 1,611,153 215,686 — 1,415,613
Schedule of Foreign Currency Risk Exposures	The Group’s principal foreign currency risk exposures for the years ended March 31, 2018 and 2019 are as follows. (Millions of USD) As of As of Net exposure (liability) 78 (174 )
Schedule of Aging of Trade and Other Receivables	The aging of trade and other receivables is as follows: (Millions of Yen) Days past due As of As of Current 964,845 831,985 Within 90 days 4,991 1,684 Over 90 days and within 1 year 729 363 Over 1 year 173 108 Total 970,740 834,142
Schedule of Changes in Allowance for Doubtful Accounts	The changes in allowance for doubtful accounts are as follows: (Millions of Yen) Year ended Year ended Balance at beginning of the year 5,878 5,854 Increase during the year 1,776 1,529 Decrease during the year (696 ) (1,513 ) Other 183 7 Balance at end of the year 7,142 5,878
Summary of financial guarantee contracts	The maximum amounts of guarantees that are extended by the Group are described in Note 34 “Loan Guarantees”. As of March 31, 2019 (Millions of Yen) Carrying Total Within 1 year Over 1 year but within 5 years Over 5 years Trade and other payables 1,611,403 1,611,403 1,611,403 — — Borrowings 1,922,476 1,922,476 326,571 657,235 938,670 Bonds 280,000 280,000 60,000 100,000 120,000 Lease liabilities 46,754 46,754 8,783 21,034 16,936 Commercial paper 120,000 120,000 120,000 — — Derivatives 7,519 7,019 2,656 4,363 — Total 3,988,154 3,987,654 2,129,414 782,633 1,075,606 As of March 31, 2018 (Millions of Yen) Carrying Total Within 1 year Over 1 year but within 5 years Over 5 years Trade and other payables 1,580,597 1,580,597 1,580,597 — — Borrowings 1,723,290 1,723,290 322,133 584,131 817,024 Bonds 295,696 295,700 85,700 140,000 70,000 Lease liabilities 49,768 49,768 8,550 22,582 18,635 Commercial paper 89,000 89,000 89,000 — — Derivatives 7,246 8,080 2,279 5,478 323 Total 3,745,600 3,746,436 2,088,260 752,192 905,983
Summary of Derivative assets and liabilities as hedging instruments	Derivative assets and liabilities designated as hedging instruments As of March 31, 2019 (Millions of Yen) Types of hedges Derivative assets and liabilities Notional Carrying amount Total Settlement in Assets Liabilities Cash flow hedge Foreign exchange forward contract 217,369 6,762 1,752 750 Interest rate swap 264,704 252,848 730 6,509 Currency swap 67,353 66,280 9,462 — Commodity swap 2,529 1,058 1,519 — Total 551,957 326,949 13,466 7,260 As of March 31, 2018 (Millions of Yen) Types of hedges Derivative assets and liabilities Notional Carrying amount Total Settlement in Assets Liabilities Cash flow hedge Foreign exchange forward contract 246,189 9,113 1,069 303 Interest rate swap 275,939 258,741 601 6,613 Currency swap 83,244 67,353 11,665 — Commodity swap 321 217 52 — Total 605,695 335,425 13,388 6,917
Summary of Derivative assets and liabilities not designated as hedges	Derivative assets and liabilities not designated as hedges (Millions of Yen) As of As of Assets Liabilities Assets Liabilities Foreign exchange forward contract 492 248 4 381 Interest swap — — 2 — Currency swap 97 10 118 11 Total 590 258 124 392
Summary of Changes in Fair Value of Cash Flow Hedges	Changes in fair value of cash flow hedges The changes in fair value of hedging instruments designated as cash flow hedges of the Group recognized in other comprehensive income in the consolidated statements of comprehensive income or loss are as follows. Year ended March 31, 2019 (Millions of Yen) Risk classification Beginning of Changes in fair Amount End of the The account in which the Foreign currency risk 426 4,407 (4,186 ) 646 Other operating income/Other operating expenses Interest rate risk (5,559 ) 228 5 (5,326 ) Finance income/Finance costs Other 52 1,519 (52 ) 1,519 — Total (5,080 ) 6,155 (4,234 ) (3,159 ) Year ended March 31, 2018 (Millions of Yen) Risk classification Beginning of Changes in fair Amount End of the The account in which the Foreign currency risk (682 ) (3,626 ) 4,734 426 Other operating income/Other operating expenses Interest rate risk (6,762 ) 1,222 (18 ) (5,559 ) Finance income/Finance costs Other 37 52 (37 ) 52 — Total (7,407 ) (2,351 ) 4,678 (5,080 )
Currency risk [member]
Statement [LineItems]
Schedule of Impact on Profit Before Income Taxes in the Consolidated Statement of Profit or Loss	In this analysis, the impacts on the assets and liabilities denominated in foreign currencies as of March 31, 2018 and 2019 are estimated by assuming that variables, such as outstanding balances and interest rates, are constant. (Millions of Yen) Year ended Year ended Impacts on profit before income taxes (86 ) 185
Interest rate risk [member]
Statement [LineItems]
Schedule of Impact on Profit Before Income Taxes in the Consolidated Statement of Profit or Loss	In this analysis, all other variables are assumed to be constant. (Millions of Yen) Year ended Year ended Impacts on profit before income taxes (6,043 ) (5,787 )

Related Parties (Tables)

Related Parties (Tables)	12 Months Ended
	Mar. 31, 2019
Text block [abstract]
Summary of Transactions with Related Parties	Details of significant transactions with related parties are as follows: Year ended March 31, 2019 (Millions of Yen) Category Name Description of Amount Account Outstanding Associate Nippon Steel & Sumikin Bussan Corporation Sells steel products 1,170,241 Trade and other receivables 46,251 The terms and conditions applied to related party transactions are determined based on terms equivalent to those that prevail in arm’s length transactions. Year ended March 31, 2018 (Millions of Yen) Category Name Description of Amount Account Outstanding Associate Nippon Steel & Sumikin Bussan Corporation Sells steel products 849,244 Trade and other receivables 39,236
Summary of Compensation Paid to Directors	Compensation paid to the directors of the Group is as follows: (Millions of Yen) Year ended Year ended Year ended Salary 935 857 964

Commitments (Tables)

Commitments (Tables)	12 Months Ended
	Mar. 31, 2019
Text block [abstract]
Significant Commitments Related to the Acquisition of Assets	Significant commitments related to the acquisition of assets are as follows: (Millions of Yen) As of As of Contractual commitments related to acquisition of property, plant and equipment and intangible assets 393,230 316,808

Loan Guarantees (Tables)

Loan Guarantees (Tables)	12 Months Ended
	Mar. 31, 2019
Investments accounted for using equity method [abstract]
Guarantees for Bank Loans of its Joint Ventures and Associates Which Would Require the Group to Repay the Loan in the Event of Default	The Group provides guarantees for the bank loans of its joint ventures and associates which would require the Group to repay the loan in the event of a default. (Millions of Yen) As of As of Guarantees for the bank loans of joint ventures and associates 62,506 82,721

Significant Accounting Polici_4

Significant Accounting Policies - Additional Information (Detail)	12 Months Ended
	Mar. 31, 2019SubsidiaryAffiliates
Statement [LineItems]
Number of consolidated subsidiaries	420
Number of expanded consolidated subsidiaries	46
Number of newly acquired companies	45
Number of newly established companies	1
Number of liquidating companies	8
Number of companies merged	6
Equity method investment number of affiliates | Affiliates	119
Increase in equity method investment number of affiliates | Affiliates	4
Decrease in equity method investment number of affiliates | Affiliates	8
Bottom of range [member]
Statement [LineItems]
Proportion of voting rights held in associate	20.00%
Top of range [member]
Statement [LineItems]
Proportion of voting rights held in associate	50.00%

Significant Accounting Polici_5

Significant Accounting Policies - Summary of Estimated Useful Lives of Property, Plant and Equipment (Detail)	12 Months Ended
	Mar. 31, 2019
Buildings [member]
Disclosure of detailed information about property, plant and equipment [line items]
Property plant and equipment	Principally 31 years
Machinery [member]
Disclosure of detailed information about property, plant and equipment [line items]
Property plant and equipment	Principally 14 years

Significant Accounting Polici_6

Significant Accounting Policies - Summary of Estimated Useful Lives of Intangible Assets (Detail)	12 Months Ended
	Mar. 31, 2019
Computer software [member]
Disclosure of detailed information about intangible assets [line items]
Intangible assets other than goodwill	Principally 5 years
Mining rights [member]
Disclosure of detailed information about intangible assets [line items]
Intangible assets other than goodwill	Principally 25 years

New Accounting Standards and _2

New Accounting Standards and Interpretations Not Yet Applied - Additional Information (Detail) ¥ in Millions	12 Months Ended
	Mar. 31, 2019JPY (¥)
In accordance with IFRS 16 [member] | Assets and liabilities [member]
Disclosure of expected impact of initial application of new standards or interpretations [line items]
Increase in accounting estimate	¥ 31,944

Segment Information - Additiona

Segment Information - Additional Information (Detail)	12 Months Ended
	Mar. 31, 2019Segment
Disclosure of operating segments [abstract]
Number of operating segments	4

Segment Information - Summary o

Segment Information - Summary of Segment Revenue, Segment Profit, Segment Assets and Liabilities and Other Items (Detail) - JPY (¥) ¥ in Millions		12 Months Ended
		Mar. 31, 2019		Mar. 31, 2018		Mar. 31, 2017
Revenue
Revenue from external customers		¥ 6,177,947		¥ 5,712,965		¥ 4,696,828
Total		6,177,947		5,712,965		4,696,828
Segment profit		336,941		288,700		169,878
Other items
Finance income		6,104		7,644		6,322
Finance costs		22,445		24,584		21,586
Depreciation and amortization		408,616		366,565		330,912
Share of profit in investments accounted for using the equity method		86,411		65,657		44,118
Segment assets		8,049,528		7,756,134
Investments accounted for using the equity method		793,146		799,239
Capital expenditure		440,830		423,428		362,525
Segment liabilities (Interest-bearing debt)		2,369,231		2,157,755
Steelmaking and Steel Fabrication [member]
Revenue
Revenue from external customers		5,408,633
Engineering and Construction [member]
Revenue
Revenue from external customers		321,346
Chemicals and Materials [member]
Revenue
Revenue from external customers		243,014
System Solutions [member]
Revenue
Revenue from external customers		204,952
Operating segments [member] | Steelmaking and Steel Fabrication [member]
Revenue
Revenue from external customers		5,408,633		4,983,335		4,016,670
Inter-segment revenue or transfers		45,902		33,910		35,590
Total		5,454,536		5,017,245		4,052,261
Segment profit		274,672		245,708		138,017
Other items
Finance income				4,983		5,566
Finance costs				20,080		17,831
Depreciation and amortization		398,702		330,393		294,008
Share of profit in investments accounted for using the equity method		76,337		116,408		70,723
Segment assets		7,404,841		7,003,681
Investments accounted for using the equity method		672,853		950,887
Capital expenditure		431,775		390,623		335,733
Segment liabilities (Interest-bearing debt)		2,365,587		2,057,997
Operating segments [member] | Engineering and Construction [member]
Revenue
Revenue from external customers		321,346		260,908		234,861
Inter-segment revenue or transfers		35,360		33,360		32,683
Total		356,707		294,268		267,545
Segment profit		9,474		9,110		6,838
Other items
Finance income				180		124
Finance costs				44		118
Depreciation and amortization		2,605		2,489		2,653
Share of profit in investments accounted for using the equity method		801		378		655
Segment assets		289,083		247,696
Investments accounted for using the equity method		6,313		4,393
Capital expenditure		3,021		6,301		5,637
Segment liabilities (Interest-bearing debt)		5,937		8,313
Operating segments [member] | Chemicals and Materials [member]
Revenue
Revenue from external customers		243,014		234,108		203,115
Inter-segment revenue or transfers		4,052		3,709		5,630
Total		247,067		237,817		208,746
Segment profit		25,095		17,399		6,304
Other items
Finance income				38		36
Finance costs				172		233
Depreciation and amortization		6,644		7,329		8,227
Share of profit in investments accounted for using the equity method		1,339		148		920
Segment assets		194,622		184,988
Investments accounted for using the equity method		23,629		24,843
Capital expenditure		8,855		8,497		9,229
Segment liabilities (Interest-bearing debt)		7,075		11,519
Operating segments [member] | System Solutions [member]
Revenue
Revenue from external customers		204,952		190,310		178,242
Inter-segment revenue or transfers		62,550		53,889		54,270
Total		267,503		244,200		232,512
Segment profit		26,576		23,292		22,113
Other items
Finance income				146		133
Finance costs				11		28
Depreciation and amortization		4,872		4,646		4,174
Share of profit in investments accounted for using the equity method		(5)		(10)		21
Segment assets		231,994		223,601
Investments accounted for using the equity method		309		17
Capital expenditure		2,542		7,638		4,343
Segment liabilities (Interest-bearing debt)		2,631		3,693
Operating segments [member] | Sub Total [member]
Revenue
Revenue from external customers		6,177,947		5,668,663		4,632,890
Inter-segment revenue or transfers		147,867		124,868		128,175
Total		6,325,814		5,793,531		4,761,065
Segment profit		335,818		295,510		173,274
Other items
Finance income				5,348		5,860
Finance costs				20,309		18,212
Depreciation and amortization		412,825		344,859		309,064
Share of profit in investments accounted for using the equity method		78,473		116,925		72,320
Segment assets		8,120,542		7,659,967
Investments accounted for using the equity method		703,105		980,142
Capital expenditure		446,194		413,061		354,943
Segment liabilities (Interest-bearing debt)		2,381,231		2,081,524
Adjustments [member]
Revenue
Inter-segment revenue or transfers	[1]	(147,867)	[2]	(124,868)	[3]	(128,175)	[4]
Total	[1]	(147,867)	[2]	(124,868)	[3]	(128,175)	[4]
Segment profit	[1]	1,122	[2]	2,030	[3]	1,256	[4]
Other items
Finance income	[1]			(202)	[3]	(206)	[4]
Finance costs	[1]			(202)	[3]	(206)	[4]
Depreciation and amortization	[1]	(4,208)	[2]	(4,140)	[3]	(4,313)	[4]
Share of profit in investments accounted for using the equity method	[1]	7,938	[2]	5,750	[3]	6,859	[4]
Segment assets	[1]	(71,013)	[2]	(67,554)	[3]
Investments accounted for using the equity method	[1]	90,041	[2]	83,614	[3]
Capital expenditure	[1]	(5,363)	[2]	(1,130)	[3]	(3,905)	[4]
Segment liabilities (Interest-bearing debt)	[1]	¥ (12,000)	[2]	(12,527)	[3]
Before application of IFRS adjustments [member]
Revenue
Revenue from external customers				5,668,663		4,632,890
Total				5,668,663		4,632,890
Segment profit				297,541		174,531
Other items
Finance income				5,146		5,654
Finance costs				20,106		18,006
Depreciation and amortization				340,719		304,751
Share of profit in investments accounted for using the equity method				122,675		79,180
Segment assets				7,592,413
Investments accounted for using the equity method				1,063,757
Capital expenditure				411,930		351,038
Segment liabilities (Interest-bearing debt)				2,068,996
IFRS adjustments [member]
Revenue
Revenue from external customers				44,302		63,937
Total				44,302		63,937
Segment profit				(8,840)		(4,652)
Other items
Finance income				2,498		668
Finance costs				4,477		3,579
Depreciation and amortization				25,845		26,161
Share of profit in investments accounted for using the equity method				(57,018)		(35,062)
Segment assets				163,721
Investments accounted for using the equity method				(264,517)
Capital expenditure				11,497		¥ 11,486
Segment liabilities (Interest-bearing debt)				¥ 88,759
[1]	The adjustments of segment liabilities include the elimination of the Steelmaking and Steel Fabrication segment's borrowings from the System Solutions segment.
[2]	The adjustments of segment profit of 1,122 million yen include investment return of 8,237 million yen from the equity method associate Nippon Steel Kowa Real Estate Co., Ltd., and elimination of inter-segment revenue or transfers of (7,114) million yen.
[3]	The adjustments of segment profit of 2,030 million yen include investment return of 5,929 million yen from the equity method associate Nippon Steel Kowa Real Estate Co., Ltd., and elimination of inter-segment revenue or transfers of (3,899) million yen.
[4]	The adjustments of segment profit of 1,256 million yen include investment return of 6,524 million yen from the equity method associate Nippon Steel Kowa Real Estate Co., Ltd., investment return of 629 million yen from the equity method associate SUMCO Corporation, and elimination of inter-segment revenue or transfers of (5,897) million yen.

Segment Information - Summary_2

Segment Information - Summary of Segment Revenue, Segment Profit, Segment Assets and Liabilities and Other Items (Parenthetical) (Detail) - JPY (¥) ¥ in Millions		12 Months Ended
		Mar. 31, 2019		Mar. 31, 2018		Mar. 31, 2017
Disclosure of operating segments [line items]
Segment profit		¥ 336,941		¥ 288,700		¥ 169,878
Revenue		6,177,947		5,712,965		4,696,828
Adjustments [member]
Disclosure of operating segments [line items]
Segment profit	[1]	1,122	[2]	2,030	[3]	1,256	[4]
Revenue	[1]	(147,867)	[2]	(124,868)	[3]	(128,175)	[4]
Nippon Steel Kowa Real Estate Co. Ltd. [member] | Adjustments [member]
Disclosure of operating segments [line items]
Return investments accounted for using the equity method		8,237		5,929		6,524
SUMCO Corporation [member] | Adjustments [member]
Disclosure of operating segments [line items]
Return investments accounted for using the equity method						629
Inter-segment revenue [member] | Adjustments [member]
Disclosure of operating segments [line items]
Revenue		¥ (7,114)		¥ (3,899)		¥ (5,897)
[1]	The adjustments of segment liabilities include the elimination of the Steelmaking and Steel Fabrication segment's borrowings from the System Solutions segment.
[2]	The adjustments of segment profit of 1,122 million yen include investment return of 8,237 million yen from the equity method associate Nippon Steel Kowa Real Estate Co., Ltd., and elimination of inter-segment revenue or transfers of (7,114) million yen.
[3]	The adjustments of segment profit of 2,030 million yen include investment return of 5,929 million yen from the equity method associate Nippon Steel Kowa Real Estate Co., Ltd., and elimination of inter-segment revenue or transfers of (3,899) million yen.
[4]	The adjustments of segment profit of 1,256 million yen include investment return of 6,524 million yen from the equity method associate Nippon Steel Kowa Real Estate Co., Ltd., investment return of 629 million yen from the equity method associate SUMCO Corporation, and elimination of inter-segment revenue or transfers of (5,897) million yen.

Segment Information - Summary_3

Segment Information - Summary of Geographic Areas (Detail) - JPY (¥) ¥ in Millions	12 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Mar. 31, 2017
Disclosure of geographical areas [line items]
Revenue	¥ 6,177,947	¥ 5,712,965	¥ 4,696,828
Non-current assets	3,413,896	3,272,335
Japan [member]
Disclosure of geographical areas [line items]
Revenue	4,053,188	3,729,176	2,980,400
Non-current assets	2,978,818	2,854,097
Overseas [member]
Disclosure of geographical areas [line items]
Revenue	2,124,758	1,983,789	1,716,427
Non-current assets	435,078	418,238
Asia [Member]
Disclosure of geographical areas [line items]
Revenue	1,310,890	1,274,380	1,068,459
Other [member]
Disclosure of geographical areas [line items]
Revenue	¥ 813,868	¥ 709,409	¥ 647,967

Segment Information - Summary_4

Segment Information - Summary of Revenue from Major Customers (Detail) - JPY (¥) ¥ in Millions	12 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Mar. 31, 2017
Disclosure of major customers [line items]
Revenue	¥ 6,177,947	¥ 5,712,965	¥ 4,696,828
Steelmaking and Steel Fabrication [member] | Nippon Steel and Sumikin Bussan Corporation [member]
Disclosure of major customers [line items]
Revenue	1,170,241	849,244	744,657
Steelmaking and Steel Fabrication [member] | Sumitomo Corporation [member]
Disclosure of major customers [line items]
Revenue	762,888	772,942	¥ 674,139
Steelmaking and Steel Fabrication [member] | Metal one corporation [member]
Disclosure of major customers [line items]
Revenue	¥ 631,639	¥ 592,146

Business Combinations - Additio

Business Combinations - Additional Information (Detail) - JPY (¥) ¥ in Millions	Mar. 28, 2019	Mar. 27, 2019	Mar. 13, 2017	Mar. 12, 2017	Mar. 31, 2019	Mar. 31, 2017	Jun. 01, 2018
Disclosure of detailed information about business combination [line items]
Proceeds from equity financing					¥ 67,235
OvakoAB [member]
Disclosure of detailed information about business combination [line items]
Cash consideration					51,767		¥ 51,767
Acquisition-related costs recognized as selling, general and administrative expenses in the consolidated statements of profit and loss					1,215
Sanyo Special Steel Co Ltd [member]
Disclosure of detailed information about business combination [line items]
Cash consideration					67,235
Acquisition-related costs recognized as selling, general and administrative expenses in the consolidated statements of profit and loss					276
Percentage of equity interests acquired	36.20%
Proportion of ownership interests held by company	51.50%	15.30%
Loss recognized as a result of remeasuring previously held interest to fair value					(4,592)
Bargain purchase gain					¥ 13,578
Nisshin Steel Co Ltd [member]
Disclosure of detailed information about business combination [line items]
Cash consideration						¥ 75,972
Acquisition-related costs recognized as selling, general and administrative expenses in the consolidated statements of profit and loss						¥ 627
Percentage of equity interests acquired			43.00%
Proportion of ownership interests held by company			51.00%	8.00%

Business Combinations - Details

Business Combinations - Details of consideration transferred (Detail) - JPY (¥) ¥ in Millions	Mar. 31, 2019	Jun. 01, 2018	Mar. 31, 2017
OvakoAB [member]
Disclosure of consideration transferred business combinations [line items]
Cash	¥ 51,767	¥ 51,767
Total consideration transferred	51,767
Sanyo Special Steel Co Ltd [member]
Disclosure of consideration transferred business combinations [line items]
Cash	67,235
Fair value of equity interests held before the acquisition date	13,737
Total consideration transferred	¥ 80,972
Nisshin Steel Co Ltd [member]
Disclosure of consideration transferred business combinations [line items]
Cash			¥ 75,972
Fair value of equity interests held before the acquisition date			14,781
Total consideration transferred			¥ 90,753

Business Combinations - Summary

Business Combinations - Summary of Fair Value of Identifiable Assets Acquired and Liabilities Assumed (Detail) - JPY (¥) ¥ in Millions	Mar. 31, 2019	Mar. 31, 2018	Mar. 31, 2017
Disclosure of detailed information about business combination [line items]
Total equity attributable to owners of the parent	¥ 3,230,788	¥ 3,136,991
OvakoAB [member]
Disclosure of detailed information about business combination [line items]
Current asset	63,555
Non-current assets	53,302
Total assets	116,858
Current liabilities	70,691
Non-current liabilities	17,032
Total liabilities	87,724
Total identifiable net assets acquired	(29,133)
Total equity attributable to owners of the parent	29,133
Total consideration transferred	51,767
Goodwill	22,634
Sanyo Special Steel Co Ltd [member]
Disclosure of detailed information about business combination [line items]
Current asset	210,344
Non-current assets	75,075
Total assets	285,419
Current liabilities	61,789
Non-current liabilities	38,804
Total liabilities	100,593
Total identifiable net assets acquired	184,826
Non-controlling interests	90,274
Total equity attributable to owners of the parent	94,551
Total consideration transferred	80,972
Bargain purchase gain	¥ 13,578
Nisshin Steel Co Ltd [member]
Disclosure of detailed information about business combination [line items]
Current asset			¥ 246,040
Non-current assets			423,937
Total assets			669,978
Current liabilities			224,318
Non-current liabilities			259,936
Total liabilities			484,255
Total identifiable net assets acquired			185,722
Non-controlling interests			98,105
Total equity attributable to owners of the parent			87,616
Total consideration transferred			90,753
Goodwill			¥ 3,136

Business Combinations - Summa_2

Business Combinations - Summary of Net Cash used in the transaction (Detail) - JPY (¥) ¥ in Millions	Mar. 31, 2019	Jun. 01, 2018	Mar. 31, 2017
OvakoAB [member]
Disclosure of detailed information about business combination [line items]
Cash consideration transferred	¥ 51,767	¥ 51,767
Cash and cash equivalents held by the acquiree at the acquisition date	(5,961)
Net cash provided in the transaction	45,805
Sanyo Special Steel Co Ltd [member]
Disclosure of detailed information about business combination [line items]
Cash consideration transferred	67,235
Cash and cash equivalents held by the acquiree at the acquisition date	(79,196)
Net cash provided in the transaction	¥ (11,961)
Nisshin Steel Co Ltd [member]
Disclosure of detailed information about business combination [line items]
Cash consideration transferred			¥ 75,972
Cash and cash equivalents held by the acquiree at the acquisition date			(23,079)
Net cash provided in the transaction			¥ 52,892

Business Combinations - Summa_3

Business Combinations - Summary of Revenue and Profit or Loss of the Group in Business Combination (Detail) - JPY (¥) ¥ in Millions	12 Months Ended
	Mar. 31, 2019	Mar. 31, 2017
Sanyo Special Steel Co Ltd [member]
Disclosure of detailed information about business combination [line items]
Revenue	¥ 6,363,765
Profit before income taxes	¥ 259,145
Nisshin Steel Co Ltd [member]
Disclosure of detailed information about business combination [line items]
Revenue		¥ 5,222,392
Profit before income taxes		¥ 199,831

Cash and Cash Equivalents - Sum

Cash and Cash Equivalents - Summary of Components of Cash and Cash Equivalents (Detail) - JPY (¥) ¥ in Millions	Mar. 31, 2019	Mar. 31, 2018	Mar. 31, 2017	Mar. 31, 2016
Cash and cash equivalents [abstract]
Cash	¥ 159,636	¥ 138,702	¥ 119,793
Cash equivalents	3,540	4,166	4,135
Total	¥ 163,176	¥ 142,869	¥ 123,929	¥ 121,183

Trade and Other Receivables- Su

Trade and Other Receivables- Summary of Components of Trade and Other Receivables (Detail) - JPY (¥) ¥ in Millions	Mar. 31, 2019	Mar. 31, 2018
Trade and other receivables [abstract]
Notes and accounts receivable	¥ 842,573	¥ 730,805
Other	128,166	103,336
Allowance for doubtful receivables	(2,407)	(2,101)
Total	¥ 968,333	¥ 832,040

Inventories - Summary of Invent

Inventories - Summary of Inventories (Detail) - JPY (¥) ¥ in Millions	Mar. 31, 2019	Mar. 31, 2018
Classes of current inventories [abstract]
Merchandise and finished goods	¥ 831,597	¥ 701,173
Work in progress	87,814	72,425
Raw materials and supplies	647,704	626,222
Total	¥ 1,567,116	¥ 1,399,821

Assets Pledged as Collateral -

Assets Pledged as Collateral - Summary of Assets Pledged as Collateral (Detail) - JPY (¥) ¥ in Millions	Mar. 31, 2019	Mar. 31, 2018
Statement [LineItems]
Assets pledged as collateral for liabilities or contingent liabilities	¥ 35,233	¥ 26,373
Land [member]
Statement [LineItems]
Assets pledged as collateral for liabilities or contingent liabilities	11,432	10,855
Buildings and Structures [member]
Statement [LineItems]
Assets pledged as collateral for liabilities or contingent liabilities	4,853	3,784
Machinery Equipment And Vehicles [member]
Statement [LineItems]
Assets pledged as collateral for liabilities or contingent liabilities	5,471	6,826
Other [member]
Statement [LineItems]
Assets pledged as collateral for liabilities or contingent liabilities	¥ 13,475	¥ 4,907

Secured Debt - Summary of Secur

Secured Debt - Summary of Secured Debt (Detail) - JPY (¥) ¥ in Millions	Mar. 31, 2019	Mar. 31, 2018
Statement [LineItems]
Secured debts	¥ 10,345	¥ 6,801
Short-term borrowings [member]
Statement [LineItems]
Secured debts	3,635	970
Long-term borrowings [member]
Statement [LineItems]
Secured debts	6,242	5,383
Other Debt [member]
Statement [LineItems]
Secured debts	¥ 467	¥ 447

Assets Pledged as Collateral _2

Assets Pledged as Collateral - Additional Information (Detail) - JPY (¥) ¥ in Millions	Mar. 31, 2019	Mar. 31, 2018
Disclosure assets pledged as collateral [abstract]
Shares Associates Pledge As Collateral	¥ 1,301	¥ 1,261

Property Plant And Equipment -

Property Plant And Equipment - Schedule Of Property Plant And Equipment (Detail) - JPY (¥) ¥ in Millions	12 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Disclosure of detailed information about property, plant and equipment [line items]
Beginning Balance	¥ 3,123,857	¥ 3,092,202
Acquisitions and reclassified from construction in progress	468,557	402,200
Acquisitions through business combinations	94,331
Disposals and sales	(19,788)	(11,249)
Depreciation	(387,347)	(344,599)
Impairment losses		(15,401)
Effects of changes in foreign exchange rates	(32,941)	705
Ending Balance	3,246,669	3,123,857
Gross carrying amount [member]
Disclosure of detailed information about property, plant and equipment [line items]
Beginning Balance	12,442,823	12,162,552
Ending Balance	13,059,068	12,442,823
Accumulated depreciation, amortisation and impairment [member]
Disclosure of detailed information about property, plant and equipment [line items]
Beginning Balance	9,318,966	9,070,350
Ending Balance	9,812,398	9,318,966
Land [member]
Disclosure of detailed information about property, plant and equipment [line items]
Beginning Balance	652,364	654,349
Acquisitions and reclassified from construction in progress	5,967	1,831
Acquisitions through business combinations	9,653
Disposals and sales	(5,258)	(2,858)
Impairment losses		(536)
Effects of changes in foreign exchange rates	(1,224)	(421)
Ending Balance	661,502	652,364
Land [member] | Gross carrying amount [member]
Disclosure of detailed information about property, plant and equipment [line items]
Beginning Balance	701,984	705,539
Ending Balance	710,235	701,984
Land [member] | Accumulated depreciation, amortisation and impairment [member]
Disclosure of detailed information about property, plant and equipment [line items]
Beginning Balance	49,620	51,189
Ending Balance	48,733	49,620
Buildings [member]
Disclosure of detailed information about property, plant and equipment [line items]
Beginning Balance	819,277	815,580
Acquisitions and reclassified from construction in progress	78,086	71,336
Acquisitions through business combinations	20,579
Disposals and sales	(3,660)	(4,081)
Depreciation	(58,817)	(58,469)
Impairment losses		(5,955)
Effects of changes in foreign exchange rates	(190)	868
Ending Balance	855,274	819,277
Buildings [member] | Equipment Under Finance Lease [member]
Disclosure of detailed information about property, plant and equipment [line items]
Beginning Balance	10,748	11,895
Ending Balance	10,024	10,748
Buildings [member] | Gross carrying amount [member]
Disclosure of detailed information about property, plant and equipment [line items]
Beginning Balance	2,607,700	2,555,698
Ending Balance	2,730,502	2,607,700
Buildings [member] | Accumulated depreciation, amortisation and impairment [member]
Disclosure of detailed information about property, plant and equipment [line items]
Beginning Balance	1,788,422	1,740,118
Ending Balance	1,875,228	1,788,422
Machinery Equipment And Vehicles [member]
Disclosure of detailed information about property, plant and equipment [line items]
Beginning Balance	1,286,908	1,266,968
Acquisitions and reclassified from construction in progress	363,975	277,566
Acquisitions through business combinations	56,261
Disposals and sales	(6,037)	(2,637)
Depreciation	(272,371)	(257,642)
Impairment losses		(8,344)
Effects of changes in foreign exchange rates	(25,447)	10,997
Ending Balance	1,403,287	1,286,908
Machinery Equipment And Vehicles [member] | Equipment Under Finance Lease [member]
Disclosure of detailed information about property, plant and equipment [line items]
Beginning Balance	32,005	31,994
Ending Balance	31,701	32,005
Machinery Equipment And Vehicles [member] | Gross carrying amount [member]
Disclosure of detailed information about property, plant and equipment [line items]
Beginning Balance	8,215,605	7,998,199
Ending Balance	8,733,560	8,215,605
Machinery Equipment And Vehicles [member] | Accumulated depreciation, amortisation and impairment [member]
Disclosure of detailed information about property, plant and equipment [line items]
Beginning Balance	6,928,697	6,731,230
Ending Balance	7,330,272	6,928,697
Tools, furniture and fixtures [member]
Disclosure of detailed information about property, plant and equipment [line items]
Beginning Balance	53,226	48,413
Acquisitions and reclassified from construction in progress	85,546	24,810
Acquisitions through business combinations	1,082
Disposals and sales	(4,570)	(621)
Depreciation	(46,659)	(19,000)
Impairment losses		(564)
Effects of changes in foreign exchange rates	719	189
Ending Balance	89,343	53,226
Tools, furniture and fixtures [member] | Equipment Under Finance Lease [member]
Disclosure of detailed information about property, plant and equipment [line items]
Beginning Balance	4,069	2,893
Ending Balance	3,241	4,069
Tools, furniture and fixtures [member] | Gross carrying amount [member]
Disclosure of detailed information about property, plant and equipment [line items]
Beginning Balance	327,419	317,753
Ending Balance	407,619	327,419
Tools, furniture and fixtures [member] | Accumulated depreciation, amortisation and impairment [member]
Disclosure of detailed information about property, plant and equipment [line items]
Beginning Balance	274,193	269,340
Ending Balance	318,276	274,193
Leased [member]
Disclosure of detailed information about property, plant and equipment [line items]
Beginning Balance	46,823	46,783
Acquisitions and reclassified from construction in progress	7,812	10,401
Disposals and sales	(131)	(246)
Depreciation	(9,498)	(9,486)
Effects of changes in foreign exchange rates	(38)	(627)
Ending Balance	44,967	46,823
Leased [member] | Equipment Under Finance Lease [member]
Disclosure of detailed information about property, plant and equipment [line items]
Beginning Balance	46,823	46,783
Ending Balance	44,967	46,823
Leased [member] | Gross carrying amount [member]
Disclosure of detailed information about property, plant and equipment [line items]
Beginning Balance	276,851	277,165
Ending Balance	280,382	276,851
Leased [member] | Accumulated depreciation, amortisation and impairment [member]
Disclosure of detailed information about property, plant and equipment [line items]
Beginning Balance	230,027	230,382
Ending Balance	235,414	230,027
Construction in progress [member]
Disclosure of detailed information about property, plant and equipment [line items]
Beginning Balance	265,258	260,106
Acquisitions and reclassified from construction in progress	(72,830)	16,255
Acquisitions through business combinations	6,755
Disposals and sales	(129)	(803)
Effects of changes in foreign exchange rates	(6,758)	(10,300)
Ending Balance	192,294	265,258
Construction in progress [member] | Gross carrying amount [member]
Disclosure of detailed information about property, plant and equipment [line items]
Beginning Balance	313,262	308,196
Ending Balance	196,767	313,262
Construction in progress [member] | Accumulated depreciation, amortisation and impairment [member]
Disclosure of detailed information about property, plant and equipment [line items]
Beginning Balance	48,003	48,089
Ending Balance	¥ 4,473	¥ 48,003

Goodwill and Intangible Asset_2

Goodwill and Intangible Assets - Summary of Carrying Amount of Goodwill and Intangible Assets (Detail) - JPY (¥) ¥ in Millions	12 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Disclosure of reconciliation of changes in intangible assets and goodwill [line items]
Beginning	¥ 139,395	¥ 142,237
Acquisitions	20,278	21,227
Acquisitions through business combinations	40,859
Amortization	(21,268)	(21,965)
Impairment losses	(10,963)	(2,673)
Effect of changes in foreign exchange rates	(9,367)	569
Ending	158,934	139,395
Goodwill [member]
Disclosure of reconciliation of changes in intangible assets and goodwill [line items]
Beginning	42,263	44,563
Acquisitions through business combinations	22,634
Impairment losses	(10,963)	(2,472)
Effect of changes in foreign exchange rates	(1,131)	173
Ending	52,803	42,263
Computer software [member]
Disclosure of reconciliation of changes in intangible assets and goodwill [line items]
Beginning	46,214	47,165
Acquisitions	19,470	18,698
Acquisitions through business combinations	1,891
Amortization	(17,868)	(18,443)
Impairment losses		(139)
Effect of changes in foreign exchange rates	(3,079)	(1,066)
Ending	46,629	46,214
Mining rights [member]
Disclosure of reconciliation of changes in intangible assets and goodwill [line items]
Beginning	44,221	44,630
Amortization	(2,198)	(2,306)
Effect of changes in foreign exchange rates	(4,884)	1,898
Ending	37,139	44,221
Other intangible assets [member]
Disclosure of reconciliation of changes in intangible assets and goodwill [line items]
Beginning	6,695	5,878
Acquisitions	807	2,528
Acquisitions through business combinations	16,333
Amortization	(1,202)	(1,215)
Impairment losses		(61)
Effect of changes in foreign exchange rates	(272)	(434)
Ending	¥ 22,362	¥ 6,695

Goodwill and Intangible Asset_3

Goodwill and Intangible Assets - Summary of Amortization of Intangible Assets (Detail) - JPY (¥) ¥ in Millions	12 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Mar. 31, 2017
Disclosure of detailed information about intangible assets [line items]
Acquisition cost	¥ 271,090	¥ 225,301	¥ 207,236
Accumulated amortization and accumulated impairment losses	112,155	85,905	64,999
Goodwill [member]
Disclosure of detailed information about intangible assets [line items]
Acquisition cost	66,238	44,736	44,563
Accumulated amortization and accumulated impairment losses	13,435	2,472
Computer software [member]
Disclosure of detailed information about intangible assets [line items]
Acquisition cost	115,358	97,253	87,236
Accumulated amortization and accumulated impairment losses	68,729	51,039	40,071
Mining rights [member]
Disclosure of detailed information about intangible assets [line items]
Acquisition cost	58,617	66,107	63,304
Accumulated amortization and accumulated impairment losses	21,478	21,885	18,674
Other intangible assets [member]
Disclosure of detailed information about intangible assets [line items]
Acquisition cost	30,875	17,203	12,131
Accumulated amortization and accumulated impairment losses	¥ 8,512	¥ 10,507	¥ 6,252

Interests in Subsidiaries, As_3

Interests in Subsidiaries, Associates and Others - Summary of Major Subsidiaries of the Company (Detail)	12 Months Ended
	Mar. 31, 2019
Steelmaking and Steel Fabrication [member] | Sanyo Special Steel Co Ltd [member]
Disclosure of subsidiaries [line items]
Address of subsidiary	Himeji-shi, Hyogo
Voting percentage in subsidiary	51.50%
Steelmaking and Steel Fabrication [member] | Nisshin Co Ltd [member]
Disclosure of subsidiaries [line items]
Address of subsidiary	Chiyoda-ku, Tokyo
Voting percentage in subsidiary	100.00%
Steelmaking and Steel Fabrication [member] | Nippon Steel and Sumikin Coated Sheet Corporation [member]
Disclosure of subsidiaries [line items]
Address of subsidiary	Chuo-ku, Tokyo
Voting percentage in subsidiary	100.00%
Steelmaking and Steel Fabrication [member] | Osaka Steel Co Ltd [member]
Disclosure of subsidiaries [line items]
Address of subsidiary	Osaka-shi, Osaka
Voting percentage in subsidiary	66.30%
Steelmaking and Steel Fabrication [member] | Nippon Steel and Sumikin Metal Products Co Ltd [member]
Disclosure of subsidiaries [line items]
Address of subsidiary	Koto-ku, Tokyo
Voting percentage in subsidiary	100.00%
Steelmaking and Steel Fabrication [member] | Nippon Steel and Sumikin Pipe Co Ltd [member]
Disclosure of subsidiaries [line items]
Address of subsidiary	Chiyoda-ku, Tokyo
Voting percentage in subsidiary	100.00%
Steelmaking and Steel Fabrication [member] | Kurosaki Harima Corporation [member]
Disclosure of subsidiaries [line items]
Address of subsidiary	Kitakyushu-shi, Fukuoka
Voting percentage in subsidiary	47.00%
Steelmaking and Steel Fabrication [member] | Nippon Steel and Sumikin Texeng Co Ltd [member]
Disclosure of subsidiaries [line items]
Address of subsidiary	Chiyoda-ku, Tokyo
Voting percentage in subsidiary	100.00%
Steelmaking and Steel Fabrication [member] | Nippon Steel and Sumikin Stainless Steel Corporation [member]
Disclosure of subsidiaries [line items]
Address of subsidiary	Chiyoda-ku, Tokyo
Voting percentage in subsidiary	100.00%
Steelmaking and Steel Fabrication [member] | Nippon Steel and Sumikin Logistics Co Ltd [member]
Disclosure of subsidiaries [line items]
Address of subsidiary	Chuo-ku, Tokyo
Voting percentage in subsidiary	100.00%
Steelmaking and Steel Fabrication [member] | Nippon Steel and Sumikin SG Wire Co Ltd [member]
Disclosure of subsidiaries [line items]
Address of subsidiary	Chiyoda-ku, Tokyo
Voting percentage in subsidiary	100.00%
Steelmaking and Steel Fabrication [member] | Geostr Corporation [member]
Disclosure of subsidiaries [line items]
Address of subsidiary	Bunkyo-ku, Tokyo
Voting percentage in subsidiary	42.30%
Steelmaking and Steel Fabrication [member] | Nippon Steel and Sumikin Welding Co Ltd [member]
Disclosure of subsidiaries [line items]
Address of subsidiary	Koto-ku, Tokyo
Voting percentage in subsidiary	100.00%
Steelmaking and Steel Fabrication [member] | Nippon Steel and Sumikin Drum Co Ltd [member]
Disclosure of subsidiaries [line items]
Address of subsidiary	Koto-ku, Tokyo
Voting percentage in subsidiary	100.00%
Steelmaking and Steel Fabrication [member] | Nippon Steel and Sumikin Blast Furnace Slag Cement Co Ltd [member]
Disclosure of subsidiaries [line items]
Address of subsidiary	Kitakyushu-shi, Fukuoka
Voting percentage in subsidiary	100.00%
Steelmaking and Steel Fabrication [member] | Nippon Steel and Sumikin Cement Co Ltd [member]
Disclosure of subsidiaries [line items]
Address of subsidiary	Muroran-shi, Hokkaido
Voting percentage in subsidiary	85.00%
Steelmaking and Steel Fabrication [member] | Nippon Steel and Sumikin Finance Co Ltd [member]
Disclosure of subsidiaries [line items]
Address of subsidiary	Chiyoda-ku, Tokyo
Voting percentage in subsidiary	100.00%
Steelmaking and Steel Fabrication [member] | Nippon Steel and Sumikin Stainless Steel Pipe Co Ltd [member]
Disclosure of subsidiaries [line items]
Address of subsidiary	Koga-shi, Ibaraki
Voting percentage in subsidiary	100.00%
Steelmaking and Steel Fabrication [member] | Nippon Steel and Sumikin Steel Wire Co Ltd [member]
Disclosure of subsidiaries [line items]
Address of subsidiary	Seki-shi, Gifu
Voting percentage in subsidiary	51.00%
Steelmaking and Steel Fabrication [member] | Nippon Steel and Sumikin Eco Tech Corporation [member]
Disclosure of subsidiaries [line items]
Address of subsidiary	Chuo-ku, Tokyo
Voting percentage in subsidiary	85.10%
Steelmaking and Steel Fabrication [member] | Nippon Steel and Sumikin Bussan Corporation [member]
Disclosure of subsidiaries [line items]
Address of subsidiary	Osaka-shi, Osaka
Voting percentage in subsidiary	85.00%
Steelmaking and Steel Fabrication [member] | Nippon Steel and Sumikin Shapes Corporation [member]
Disclosure of subsidiaries [line items]
Address of subsidiary	Wakayama-shi, Wakayama
Voting percentage in subsidiary	100.00%
Steelmaking and Steel Fabrication [member] | Nippon Steel And Sumikin Tubosdo Brasil Ltda [member]
Disclosure of subsidiaries [line items]
Address of subsidiary	State of Rio de Janeiro, Brazil
Voting percentage in subsidiary	100.00%
Steelmaking and Steel Fabrication [member] | NS-Siam United Steel Co Ltd [member]
Disclosure of subsidiaries [line items]
Address of subsidiary	Rayong Province, Thailand
Voting percentage in subsidiary	80.20%
Steelmaking and Steel Fabrication [member] | National Pipe Company Limited [member]
Disclosure of subsidiaries [line items]
Address of subsidiary	Eastern Province, Saudi Arabia
Voting percentage in subsidiary	51.00%
Steelmaking and Steel Fabrication [member] | Standard Steel LLC [member]
Disclosure of subsidiaries [line items]
Address of subsidiary	Pennsylvania State, United States of America
Voting percentage in subsidiary	100.00%
Steelmaking and Steel Fabrication [member] | Nippon Steel and Sumitomo Metal USA Inc [member]
Disclosure of subsidiaries [line items]
Address of subsidiary	New York State, United States of America
Voting percentage in subsidiary	100.00%
Steelmaking and Steel Fabrication [member] | PT Pelat Timah Nusantara Tbk [member]
Disclosure of subsidiaries [line items]
Address of subsidiary	Jakarta City, Indonesia
Voting percentage in subsidiary	35.00%
Steelmaking and Steel Fabrication [member] | Nippon Steel and Sumitomo Metal (Thailand) Co Ltd [member]
Disclosure of subsidiaries [line items]
Address of subsidiary	Bangkok Metropolis, Thailand
Voting percentage in subsidiary	100.00%
Steelmaking and Steel Fabrication [member] | Nippon Steel and Sumitomo Metal Australia Pty Limited [member]
Disclosure of subsidiaries [line items]
Address of subsidiary	New South Wales State, Australia
Voting percentage in subsidiary	100.00%
Steelmaking and Steel Fabrication [member] | Nippon Steel and Sumikin Steel Processing Thailand Co Ltd [member]
Disclosure of subsidiaries [line items]
Address of subsidiary	Rayong Province, Thailand
Voting percentage in subsidiary	66.50%
Steelmaking and Steel Fabrication [member] | OvakoAB [member]
Disclosure of subsidiaries [line items]
Address of subsidiary	Stockholm, Sweden
Voting percentage in subsidiary	100.00%
Engineering and Construction [member] | Nippon Steel and Sumikin Engineering Co Ltd [member]
Disclosure of subsidiaries [line items]
Address of subsidiary	Shinagawa-ku, Tokyo
Voting percentage in subsidiary	100.00%
Chemicals and Materials [member] | Nippon Steel Chemical and Material Co Ltd [member]
Disclosure of subsidiaries [line items]
Address of subsidiary	Chiyoda-ku, Tokyo
Voting percentage in subsidiary	100.00%
System Solutions [member] | NS Solutions Corporation [member]
Disclosure of subsidiaries [line items]
Address of subsidiary	Chuo-ku, Tokyo
Voting percentage in subsidiary	63.40%

Interests in Subsidiaries, As_4

Interests in Subsidiaries, Associates and Others - Summary of Major Subsidiaries of the Company (Parenthetical) (Detail)	12 Months Ended
	Mar. 31, 2019
Maximum [Member] | Steelmaking and Steel Fabrication [member]
Disclosure of subsidiaries [line items]
Percentage of voting rights	50.00%

Interests in Subsidiaries, As_5

Interests in Subsidiaries, Associates and Others - Summary of Investments in Associates (Detail) - JPY (¥) ¥ in Millions	12 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Mar. 31, 2017
Disclosure of associates [line items]
Carrying amount of investments in associates	¥ 636,216	¥ 654,214
Net profit or loss	257,579	212,210	¥ 154,483
Other comprehensive income	(172,464)	99,548	104,977
Associates [member]
Disclosure of associates [line items]
Net profit or loss	49,436	38,199	29,622
Other comprehensive income	(18,610)	(270)	11,379
Total	¥ 30,826	¥ 37,929	¥ 41,002

Interests in Subsidiaries, As_6

Interests in Subsidiaries, Associates and Others - Summary of Investments in Joint Ventures (Detail) - JPY (¥) ¥ in Millions	12 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Mar. 31, 2017
Disclosure of joint ventures [line items]
Carrying amount of investments in joint ventures	¥ 156,930	¥ 145,025
Net profit or loss	257,579	212,210	¥ 154,483
Other comprehensive income	(172,464)	99,548	104,977
Joint ventures [member]
Disclosure of joint ventures [line items]
Net profit or loss	36,975	27,458	14,495
Other comprehensive income	(6,030)	2,793	(1,108)
Total	¥ 30,944	¥ 30,251	¥ 13,386

Interests in Subsidiaries, As_7

Interests in Subsidiaries, Associates and Others - Additional Information (Detail)	Mar. 31, 2019JPY (¥)
Disclosure of Associates and Joint Venture [abstract]
Individually significant investments in associates accounted for under equity method	¥ 0
Individually significant investments in joint ventures accounted for under equity method	¥ 0

Income Taxes - Components of De

Income Taxes - Components of Deferred Tax Assets and Deferred Tax Liabilities (Detail) - JPY (¥) ¥ in Millions	12 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Mar. 31, 2017
Deferred tax assets
Accrued bonus	¥ 28,189	¥ 26,453
Defined benefit liabilities	66,924	48,011
Impairment losses on non-financial assets	17,888	11,637
Property, plant and equipment	21,552	19,482
Unused tax losses	39,280	29,330
Elimination of unrealized gains on property, plant and equipment and others	31,553	29,681
Accrued expenses for demolition and removal of fixed assets	15,024	13,807
Other	48,820	39,367
Total deferred tax assets	269,234	217,772
Deferred tax liabilities
Equity securities	(108,609)	(151,451)
Defined benefit assets	(25,167)	(33,357)
Undistributed earnings	(31,570)	(30,904)
Special tax purpose reserves	(43,782)	(62,466)
Total deferred tax liabilities	(209,130)	(278,179)
Net deferred tax assets (liabilities)	¥ 60,104	¥ (60,407)	¥ (38,993)

Income Taxes - Summary of Chang

Income Taxes - Summary of Changes in Deferred Tax Assets and Liabilities (Detail) - JPY (¥) ¥ in Millions	12 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Mar. 31, 2017
Disclosure of temporary difference, unused tax losses and unused tax credits [abstract]
Balance at beginning of the year	¥ (60,407)	¥ (38,993)
Recognized in profit or loss	88,108	19,575
Recognized in other comprehensive income	37,761	(41,003)	¥ (46,774)
Effect of changes in consolidation scope	(5,268)	14
Balance at end of the year	¥ 60,104	¥ (60,407)	¥ (38,993)

Income Taxes - Details of Deduc

Income Taxes - Details of Deductible Temporary Differences and Unused Tax Losses (Detail) - JPY (¥) ¥ in Millions	Mar. 31, 2019	Mar. 31, 2018
Disclosure of temporary difference, unused tax losses and unused tax credits [abstract]
Carryforward of unused tax losses	¥ 51,390	¥ 87,225
Deductible temporary differences	111,242	131,854
Total	¥ 162,633	¥ 219,080

Income Taxes - Summary of Compo

Income Taxes - Summary of Components of Unused Tax Losses (Detail) - JPY (¥) ¥ in Millions	Mar. 31, 2019	Mar. 31, 2018
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]
Carryforward of unused tax losses	¥ 51,390	¥ 87,225
Within 1 year [member]
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]
Carryforward of unused tax losses	3,009	30,935
Over 2 years but less than 3 years [member]
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]
Carryforward of unused tax losses	5,209	7,774
Over 3 years but less than 4 years [member]
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]
Carryforward of unused tax losses	10,640	11,426
Over 4 years but less than 5 years [member]
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]
Carryforward of unused tax losses	1,247	17,003
Over 5 years [member]
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]
Carryforward of unused tax losses	¥ 31,283	¥ 20,085

Income Taxes - Details of Incom

Income Taxes - Details of Income Tax Expense (Detail) - JPY (¥) ¥ in Millions	12 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Mar. 31, 2017
Disclosure of income tax expense [abstract]
Current taxes	¥ 79,209	¥ 79,124	¥ 49,526
Deferred taxes	(88,018)	(19,575)	(9,229)
Total	¥ (8,809)	¥ 59,549	¥ 40,297

Income Taxes - Additional Infor

Income Taxes - Additional Information (Detail) - JPY (¥) ¥ in Millions	12 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Mar. 31, 2017
Disclosure Of Income Taxes [line items]
Tax rate	30.60%	30.90%	30.90%
Reduction in deferred tax due to change in tax rate		¥ (6,253)
United States [member]
Disclosure Of Income Taxes [line items]
Tax rate	21.00%	35.00%

Income Taxes - Details of Diffe

Income Taxes - Details of Differences Between the Statutory Income Tax and Average Effective Tax Rate (Detail)	12 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Mar. 31, 2017
Reconciliation of average effective tax rate and applicable tax rate [abstract]
Statutory tax rate	30.60%	30.90%	30.90%
Share of profit in investments accounted for using the equity method	(7.30%)	(4.80%)	(4.50%)
Effects of expense not deductible for tax purposes	0.90%	0.90%	1.10%
Effects of income not taxable for tax purposes	(0.60%)	(0.60%)	(1.00%)
Effects of differences in statutory tax rates applied to companies in Japan and foreign companies	(1.80%)	(2.30%)	(2.00%)
Effects of changes in unrecognized deferred tax assets	(24.00%)	(4.00%)	(8.10%)
Other	(1.40%)	1.90%	4.30%
Average effective tax rate	(3.50%)	21.90%	20.70%

Trade and Other Payables - Summ

Trade and Other Payables - Summary of Components of Trade and Other Payables (Detail) - JPY (¥) ¥ in Millions	12 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Subclassifications of assets, liabilities and equities [abstract]
Notes and trade accounts payable	¥ 821,009	¥ 782,605
Other payables	524,167	474,903
Other	266,226	323,087
Total	¥ 1,611,403	¥ 1,580,597

Bonds, Borrowings and Lease L_3

Bonds, Borrowings and Lease Liabilities - Schedule of Details of Bonds, Borrowings and Lease Liabilities (Detail) - JPY (¥) ¥ in Millions	12 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Disclosure of detailed information about borrowings [line items]
Borrowings	¥ 2,369,231	¥ 2,157,755
Short-term borrowings [member]
Disclosure of detailed information about borrowings [line items]
Borrowings	¥ 215,393	¥ 137,323
Average interest rate	1.20%	1.00%
Current portion of long-term borrowings repayable within one year [member]
Disclosure of detailed information about borrowings [line items]
Borrowings	¥ 111,177	¥ 184,809
Average interest rate	1.00%	1.00%
Current portion of bonds repayable within one year [member]
Disclosure of detailed information about borrowings [line items]
Borrowings	¥ 60,000	¥ 85,700
Average interest rate	1.40%	1.50%
Current portion of lease liabilities repayable within one year [member]
Disclosure of detailed information about borrowings [line items]
Borrowings	¥ 8,783	¥ 8,550
Average interest rate	0.80%	0.80%
Commercial papers [member]
Disclosure of detailed information about borrowings [line items]
Borrowings	¥ 120,000	¥ 89,000
Average interest rate	0.00%	0.00%
Long-term borrowings [member]
Disclosure of detailed information about borrowings [line items]
Borrowings	¥ 1,595,905	¥ 1,401,156
Average interest rate	0.80%	0.80%
Maturity date	July 19, 2075
Noncurrent bonds [member]
Disclosure of detailed information about borrowings [line items]
Borrowings	¥ 220,000	¥ 209,996
Average interest rate	0.70%	1.00%
Maturity date	September 19, 2031
Lease liabilities [member]
Disclosure of detailed information about borrowings [line items]
Borrowings	¥ 37,970	¥ 41,218
Average interest rate	0.80%	0.80%
Maturity date	March 31, 2076

Bonds, Borrowings and Lease L_4

Bonds, Borrowings and Lease Liabilities - Schedule of Details of Bonds (Detail) - JPY (¥) ¥ in Millions	12 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Disclosure of detailed information about borrowings [line items]
Carrying Amount	¥ 2,369,231	¥ 2,157,755
Bonds [member]
Disclosure of detailed information about borrowings [line items]
Carrying Amount	¥ 280,000	295,696
Bonds [member] | Japanese Yen Corporate Bonds Maturity 2019 [member]
Disclosure of detailed information about borrowings [line items]
Issue date	Feb. 15, 1999
Carrying Amount		696
Maturity date	February 15, 2019
Bonds [member] | The 58th Issue of Unsecured Corporate Bonds [member]
Disclosure of detailed information about borrowings [line items]
Issue date	Sep. 2, 2008
Carrying Amount		30,000
Maturity date	June 20, 2018
Bonds [member] | The 59th Issue of Unsecured Corporate Bonds [member]
Disclosure of detailed information about borrowings [line items]
Issue date	Sep. 2, 2008
Carrying Amount	¥ 10,000	10,000
Maturity date	June 20, 2028
Bonds [member] | The 61st Issue of Unsecured Corporate Bonds [member]
Disclosure of detailed information about borrowings [line items]
Issue date	Dec. 2, 2008
Carrying Amount		15,000
Maturity date	September 20, 2018
Bonds [member] | The 63rd Issue of Unsecured Corporate Bonds [member]
Disclosure of detailed information about borrowings [line items]
Issue date	Jun. 9, 2009
Carrying Amount	¥ 20,000	20,000
Maturity date	June 20, 2019
Bonds [member] | The 64th Issue of Unsecured Corporate Bonds [member]
Disclosure of detailed information about borrowings [line items]
Issue date	Apr. 20, 2010
Carrying Amount	¥ 20,000	20,000
Maturity date	March 19, 2020
Bonds [member] | The 65th Issue of Unsecured Corporate Bonds [member]
Disclosure of detailed information about borrowings [line items]
Issue date	Aug. 31, 2010
Carrying Amount	¥ 15,000	15,000
Maturity date	June 19, 2020
Bonds [member] | The 67th Issue of Unsecured Corporate Bonds [member]
Disclosure of detailed information about borrowings [line items]
Issue date	May 24, 2011
Carrying Amount	¥ 30,000	30,000
Maturity date	March 19, 2021
Bonds [member] | The 65th No2 Issue Of Unsecured Corporate Bonds [member]
Disclosure of detailed information about borrowings [line items]
Issue date	May 31, 2011
Carrying Amount		10,000
Maturity date	May 31, 2018
Bonds [member] | The 68th Issue of Unsecured Corporate Bonds [member]
Disclosure of detailed information about borrowings [line items]
Issue date	Oct. 20, 2011
Carrying Amount	¥ 15,000	15,000
Maturity date	September 17, 2021
Bonds [member] | The 68th No2 Issue of Unsecured Corporate Bonds [member]
Disclosure of detailed information about borrowings [line items]
Issue date	Oct. 20, 2011
Carrying Amount		10,000
Maturity date	October 19, 2018
Bonds [member] | The 70th Issue of Unsecured Corporate Bonds [member]
Disclosure of detailed information about borrowings [line items]
Issue date	Apr. 20, 2012
Carrying Amount	¥ 10,000	10,000
Maturity date	April 19, 2019
Bonds [member] | The 69th No2 Issue of Unsecured Corporate Bonds [member]
Disclosure of detailed information about borrowings [line items]
Issue date	Jul. 20, 2012
Carrying Amount	¥ 10,000	10,000
Maturity date	June 20, 2019
Bonds [member] | The 70th No2 Issue of Unsecured Corporate Bonds [member]
Disclosure of detailed information about borrowings [line items]
Issue date	Jul. 20, 2012
Carrying Amount	¥ 20,000	20,000
Maturity date	June 20, 2022
Bonds [member] | The 1st Issue of Unsecured Corporate Bonds [member]
Disclosure of detailed information about borrowings [line items]
Issue date	Sep. 26, 2016
Carrying Amount	¥ 10,000	10,000
Maturity date	September 18, 2026
Bonds [member] | The 2nd Issue of Unsecured Corporate Bonds [member]
Disclosure of detailed information about borrowings [line items]
Issue date	Sep. 26, 2016
Carrying Amount	¥ 10,000	10,000
Maturity date	September 19, 2031
Bonds [member] | The 3rd Issue of Unsecured Corporate Bonds [member]
Disclosure of detailed information about borrowings [line items]
Issue date	May 25, 2017
Carrying Amount	¥ 10,000	10,000
Maturity date	May 20, 2024
Bonds [member] | The 4th Issue of Unsecured Corporate Bonds [member]
Disclosure of detailed information about borrowings [line items]
Issue date	May 25, 2017
Carrying Amount	¥ 10,000	10,000
Maturity date	May 20, 2027
Bonds [member] | The 5th Issue Of Unsecured Corporate Bonds [member]
Disclosure of detailed information about borrowings [line items]
Issue date	Dec. 8, 2017
Carrying Amount	¥ 10,000	10,000
Maturity date	December 20, 2024
Bonds [member] | The 6th Issue of Unsecured Corporate Bonds [member]
Disclosure of detailed information about borrowings [line items]
Issue date	Dec. 8, 2017
Carrying Amount	¥ 10,000	10,000
Maturity date	December 20, 2027
Bonds [member] | The 7th Issue of Unsecured Corporate Bonds [member]
Disclosure of detailed information about borrowings [line items]
Issue date	Jun. 12, 2018
Carrying Amount	¥ 20,000
Maturity date	June 20, 2023
Bonds [member] | The 8th Issue of Unsecured Corporate Bonds [member]
Disclosure of detailed information about borrowings [line items]
Issue date	Jun. 12, 2018
Carrying Amount	¥ 20,000
Maturity date	June 20, 2025
Bonds [member] | The 9th Issue of Unsecured Corporate Bonds [member]
Disclosure of detailed information about borrowings [line items]
Issue date	Jun. 12, 2018
Carrying Amount	¥ 20,000
Maturity date	June 20, 2028
Bonds [member] | The 19th Issue of Unsecured Corporate Bonds [member]
Disclosure of detailed information about borrowings [line items]
Issue date	Jun. 2, 2008
Carrying Amount		10,000
Maturity date	June 1, 2018
Bonds [member] | The 23rd Issue of Unsecured Corporate Bonds [member]
Disclosure of detailed information about borrowings [line items]
Issue date	Mar. 10, 2014
Carrying Amount		¥ 10,000
Maturity date	March 8, 2019
Bonds [member] | The 2nd Issue of Unsecured Corporate Bonds [member]
Disclosure of detailed information about borrowings [line items]
Issue date	Dec. 7, 2017
Carrying Amount	¥ 10,000
Maturity date	December 6, 2024

Bonds, Borrowings and Lease L_5

Bonds, Borrowings and Lease Liabilities - Schedule of Reconciliation of Changes in Liabilities Arising from Financing Activities (Detail) - JPY (¥) ¥ in Millions	12 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Disclosure of reconciliation of liabilities arising from financing activities [line items]
Beginning Balance	¥ 2,157,755	¥ 2,214,928
Cash flows from financing activities	134,760	(59,677)
Effects of changes in consolidation scope	73,880	2,759
Effects of changes in foreign exchange rates	(3,277)	(10,387)
Other	6,112	10,132
Ending Balance	2,369,231	2,157,755
Short-term borrowings [member]
Disclosure of reconciliation of liabilities arising from financing activities [line items]
Beginning Balance	137,323	142,769
Cash flows from financing activities	44,401	(7,114)
Effects of changes in consolidation scope	35,073	1,331
Effects of changes in foreign exchange rates	(1,220)	276
Other	(184)	60
Ending Balance	215,393	137,323
Commercial papers [member]
Disclosure of reconciliation of liabilities arising from financing activities [line items]
Beginning Balance	89,000	31,854
Cash flows from financing activities	23,000	57,140
Effects of changes in consolidation scope	8,000
Effects of changes in foreign exchange rates		4
Ending Balance	120,000	89,000
Long-term borrowings [member]
Disclosure of reconciliation of liabilities arising from financing activities [line items]
Beginning Balance	1,585,966	1,595,610
Cash flows from financing activities	102,850	2,672
Effects of changes in consolidation scope	20,872	1,435
Effects of changes in foreign exchange rates	(2,013)	(10,865)
Other	(593)	(2,886)
Ending Balance	1,707,083	1,585,966
Bonds [member]
Disclosure of reconciliation of liabilities arising from financing activities [line items]
Beginning Balance	295,696	396,005
Cash flows from financing activities	(25,700)	(100,000)
Effects of changes in consolidation scope	10,000
Other	3	(309)
Ending Balance	280,000	295,696
Lease liabilities [member]
Disclosure of reconciliation of liabilities arising from financing activities [line items]
Beginning Balance	49,768	48,688
Cash flows from financing activities	(9,792)	(12,377)
Effects of changes in consolidation scope	(65)	(7)
Effects of changes in foreign exchange rates	(43)	196
Other	6,886	13,267
Ending Balance	¥ 46,754	¥ 49,768

Leases - Summary of Future Mini

Leases - Summary of Future Minimum Payments under Finance Lease Contracts (Detail) - JPY (¥) ¥ in Millions	Mar. 31, 2019	Mar. 31, 2018
Disclosure of maturity analysis of finance lease payments receivable [line items]
Future minimum lease payments under finance lease contracts	¥ 46,754	¥ 49,768
Within 1 year [member]
Disclosure of maturity analysis of finance lease payments receivable [line items]
Future minimum lease payments under finance lease contracts	8,783	8,550
Over 1 but less than 5 years [member]
Disclosure of maturity analysis of finance lease payments receivable [line items]
Future minimum lease payments under finance lease contracts	21,034	22,582
Over 5 years [member]
Disclosure of maturity analysis of finance lease payments receivable [line items]
Future minimum lease payments under finance lease contracts	¥ 16,936	¥ 18,635

Leases - Summary of Future Mi_2

Leases - Summary of Future Minimum Payments under Non-Cancellable Operating Lease Contracts (Detail) - JPY (¥) ¥ in Millions	Mar. 31, 2019	Mar. 31, 2018
Disclosure of maturity analysis of operating lease payments [line items]
Future minimum lease payments under non-cancellable operating lease contracts	¥ 45,800	¥ 48,228
Within 1 year [member]
Disclosure of maturity analysis of operating lease payments [line items]
Future minimum lease payments under non-cancellable operating lease contracts	11,371	9,965
Over 1 but less than 5 years [member]
Disclosure of maturity analysis of operating lease payments [line items]
Future minimum lease payments under non-cancellable operating lease contracts	29,434	31,624
Over 5 years [member]
Disclosure of maturity analysis of operating lease payments [line items]
Future minimum lease payments under non-cancellable operating lease contracts	¥ 4,994	¥ 6,638

Leases - Additional Information

Leases - Additional Information (Detail) - JPY (¥) ¥ in Millions	12 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Disclosure of finance lease and operating lease by lessee [abstract]
Operating lease expenses under non-cancellable operating lease contracts recognized	¥ 10,356	¥ 9,597

Leases - Summary of Future Mi_3

Leases - Summary of Future Minimum Payments Expected to be Received under Non-Cancellable Operating Lease Contracts (Detail) - JPY (¥) ¥ in Millions	Mar. 31, 2019	Mar. 31, 2018
Disclosure of maturity analysis of operating lease payments [line items]
Future lease payments expected to be received under non-cancellable operating lease contracts	¥ 32,353	¥ 16,110
Within 1 year [member]
Disclosure of maturity analysis of operating lease payments [line items]
Future lease payments expected to be received under non-cancellable operating lease contracts	2,314	1,906
Over 1 but less than 5 years [member]
Disclosure of maturity analysis of operating lease payments [line items]
Future lease payments expected to be received under non-cancellable operating lease contracts	8,326	6,549
Over 5 years [member]
Disclosure of maturity analysis of operating lease payments [line items]
Future lease payments expected to be received under non-cancellable operating lease contracts	¥ 21,712	¥ 7,654

Employee Benefits - Changes in

Employee Benefits - Changes in Present Value of Defined Benefit Obligations for the Group (Detail) - Present value of defined benefit obligation [member] - JPY (¥) ¥ in Millions	12 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Disclosure of net defined benefit liability (asset) [line items]
Balance at beginning of the year	¥ 619,280	¥ 650,749
Current service cost	34,137	34,168
Interest cost	2,610	2,591
Actuarial gains and losses	6,183	296
Past service cost	(54)	(5,700)
Benefits paid	(48,542)	(55,624)
Other	17,137	(7,199)
Balance at end of the year	¥ 630,754	¥ 619,280

Employee Benefits - Additional

Employee Benefits - Additional Information (Detail) ¥ in Millions	12 Months Ended
	Mar. 31, 2019JPY (¥)yr	Mar. 31, 2018JPY (¥)yr	Mar. 31, 2017JPY (¥)
Disclosure of defined benefit plans [abstract]
Weighted average duration of the defined benefit obligations | yr	11.9	11.5
Expected contribution to defined benefit plans for the year ending March 31, 2020	¥ 12,461
Amounts recognized as expenses for defined contribution plans	6,557	¥ 5,008	¥ 4,926
Employee benefits expenses incurred	¥ 869,640	¥ 831,273	¥ 753,712

Employee Benefits - Changes i_2

Employee Benefits - Changes in Fair Value of Plan Assets for the Group (Detail) - Plan assets [member] - JPY (¥) ¥ in Millions	12 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Disclosure of net defined benefit liability (asset) [line items]
Balance at beginning of the year	¥ 554,671	¥ 545,072
Interest income	2,986	2,788
Return on plan assets, excluding interest income	(457)	29,550
Employer contributions	13,903	13,765
Benefits paid	(29,682)	(34,637)
Other	(15,174)	(1,866)
Balance at end of the year	¥ 526,246	¥ 554,671

Employee Benefits - Components

Employee Benefits - Components of Fair Value of Plan Asset by Asset Category (Detail) - JPY (¥) ¥ in Millions	Mar. 31, 2019	Mar. 31, 2018
With quoted market price in an active market [member]
Disclosure of fair value of plan assets [line items]
Bonds	¥ 80,469	¥ 83,441
Equity investments	208,456	249,400
Cash and cash equivalents	43,857	32,799
Total	332,783	365,641
With no quoted market price in an active market [member]
Disclosure of fair value of plan assets [line items]
General accounts at life insurance company	126,547	123,396
Other	66,915	65,633
Total	¥ 193,463	¥ 189,030

Employee Benefits - Significant

Employee Benefits - Significant Actuarial Assumptions Used to Determine Present Value of Defined Benefit Obligations (Detail)	Mar. 31, 2019	Mar. 31, 2018
Disclosure of defined benefit plans [abstract]
Discount rate	0.30%	0.30%

Employee Benefits - Effects on

Employee Benefits - Effects on Defined Benefit Obligations of Increase in Discount Rates (Detail) - JPY (¥) ¥ in Millions	Mar. 31, 2019	Mar. 31, 2018
Actuarial assumption of discount rates [member]
Disclosure of sensitivity analysis for actuarial assumptions [line items]
Effects of incremental increase in discount rate by 0.5%	¥ (33,151)	¥ (32,049)

Employee Benefits - Effects o_2

Employee Benefits - Effects on Defined Benefit Obligations of Increase in Discount Rates (Parenthetical) (Detail)	Mar. 31, 2019	Mar. 31, 2018
Actuarial assumption of discount rates [member]
Disclosure of sensitivity analysis for actuarial assumptions [line items]
Incremental increase percentage	0.50%	0.50%

Equity and Other Equity Items -

Equity and Other Equity Items - Total Number of Shares Authorized to be Issued and Shares Outstanding (Detail) - shares shares in Thousands	12 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Disclosure of classes of share capital [abstract]
Number of shares authorized to be issued, beginning balance	2,000,000	2,000,000
Changes	0	0
Number of shares authorized to be issued, ending balance	2,000,000	2,000,000
Number of shares outstanding, beginning balance	950,321	950,321
Changes	0	0
Number of shares outstanding, ending balance	950,321	950,321

Equity and Other Equity Items_2

Equity and Other Equity Items - Total Number of Treasury Stock Held (Detail) - shares shares in Thousands	12 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Disclosure of classes of share capital [abstract]
Number of treasury stock held by the Group, beginning balance	67,710	67,674
Changes	(37,912)	36
Number of treasury stock held by the Group, ending balance	29,797	67,710

Equity and Other Equity Items_3

Equity and Other Equity Items - Additional Information (Detail) shares in Thousands	Mar. 31, 2019shares
Nisshin Steel [member] | Treasury stock [member]
Disclosure of classes of share capital [line items]
Shares used to acquire through share exchange	38,161

Dividends - Dividends Paid (Det

Dividends - Dividends Paid (Detail) - JPY (¥) ¥ / shares in Units, ¥ in Millions	Nov. 02, 2018	Jun. 26, 2018	Oct. 27, 2017	Jun. 27, 2017	Jun. 24, 2016
Disclosure of dividend [abstract]
Total amount of dividends (Millions of Yen)	¥ 35,355	¥ 35,355	¥ 26,517	¥ 39,776	¥ 13,554
Dividends per share (Yen)	¥ 40	¥ 40	¥ 30	¥ 45	¥ 15
Record date	Sep. 30, 2018	Mar. 31, 2018	Sep. 30, 2017	Mar. 31, 2017	Mar. 31, 2016
Effective date	Dec. 3, 2018	Jun. 27, 2018	Nov. 30, 2017	Jun. 28, 2017	Jun. 27, 2016

Dividends - Dividends that Belo

Dividends - Dividends that Belong to Current Consolidated Reporting Year but Become Effective in Subsequent Consolidated Reporting Year (Detail) - JPY (¥) ¥ / shares in Units, ¥ in Millions	12 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Mar. 31, 2017
Disclosure of dividend [abstract]
Total amount of dividends (Millions of Yen)	¥ 36,880	¥ 35,355	¥ 39,776
Dividends per share (Yen)	¥ 40	¥ 40	¥ 45
Record date	Mar. 31, 2019	Mar. 31, 2018	Mar. 31, 2017
Effective date	Jun. 26, 2019	Jun. 27, 2018	Jun. 28, 2017

Revenue - Disaggregation of Rev

Revenue - Disaggregation of Revenue from Contracts with Customers and its Relationship with Segment Revenue (Detail) - JPY (¥) ¥ in Millions	12 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Mar. 31, 2017
Disclosure of disaggregation of revenue from contracts with customers [line items]
Revenue from contracts with customers	¥ 6,177,947	¥ 5,712,965	¥ 4,696,828
Japan [member]
Disclosure of disaggregation of revenue from contracts with customers [line items]
Revenue from contracts with customers	4,053,188
Asia [Member]
Disclosure of disaggregation of revenue from contracts with customers [line items]
Revenue from contracts with customers	1,310,890
Middle East [member]
Disclosure of disaggregation of revenue from contracts with customers [line items]
Revenue from contracts with customers	113,502
Europe [Member]
Disclosure of disaggregation of revenue from contracts with customers [line items]
Revenue from contracts with customers	167,473
North America [Member]
Disclosure of disaggregation of revenue from contracts with customers [line items]
Revenue from contracts with customers	284,779
Central and South America [member]
Disclosure of disaggregation of revenue from contracts with customers [line items]
Revenue from contracts with customers	188,944
Africa [Member]
Disclosure of disaggregation of revenue from contracts with customers [line items]
Revenue from contracts with customers	46,202
Pacific [Member]
Disclosure of disaggregation of revenue from contracts with customers [line items]
Revenue from contracts with customers	12,964
Steelmaking and Steel Fabrication [member]
Disclosure of disaggregation of revenue from contracts with customers [line items]
Revenue from contracts with customers	5,408,633
Steelmaking and Steel Fabrication [member] | Japan [member]
Disclosure of disaggregation of revenue from contracts with customers [line items]
Revenue from contracts with customers	3,431,461
Steelmaking and Steel Fabrication [member] | Asia [Member]
Disclosure of disaggregation of revenue from contracts with customers [line items]
Revenue from contracts with customers	1,194,440
Steelmaking and Steel Fabrication [member] | Middle East [member]
Disclosure of disaggregation of revenue from contracts with customers [line items]
Revenue from contracts with customers	113,180
Steelmaking and Steel Fabrication [member] | Europe [Member]
Disclosure of disaggregation of revenue from contracts with customers [line items]
Revenue from contracts with customers	142,335
Steelmaking and Steel Fabrication [member] | North America [Member]
Disclosure of disaggregation of revenue from contracts with customers [line items]
Revenue from contracts with customers	279,575
Steelmaking and Steel Fabrication [member] | Central and South America [member]
Disclosure of disaggregation of revenue from contracts with customers [line items]
Revenue from contracts with customers	188,473
Steelmaking and Steel Fabrication [member] | Africa [Member]
Disclosure of disaggregation of revenue from contracts with customers [line items]
Revenue from contracts with customers	46,202
Steelmaking and Steel Fabrication [member] | Pacific [Member]
Disclosure of disaggregation of revenue from contracts with customers [line items]
Revenue from contracts with customers	12,963
Engineering and Construction [member]
Disclosure of disaggregation of revenue from contracts with customers [line items]
Revenue from contracts with customers	321,346
Engineering and Construction [member] | Japan [member]
Disclosure of disaggregation of revenue from contracts with customers [line items]
Revenue from contracts with customers	264,674
Engineering and Construction [member] | Asia [Member]
Disclosure of disaggregation of revenue from contracts with customers [line items]
Revenue from contracts with customers	34,746
Engineering and Construction [member] | Middle East [member]
Disclosure of disaggregation of revenue from contracts with customers [line items]
Revenue from contracts with customers	2
Engineering and Construction [member] | Europe [Member]
Disclosure of disaggregation of revenue from contracts with customers [line items]
Revenue from contracts with customers	20,645
Engineering and Construction [member] | North America [Member]
Disclosure of disaggregation of revenue from contracts with customers [line items]
Revenue from contracts with customers	997
Engineering and Construction [member] | Central and South America [member]
Disclosure of disaggregation of revenue from contracts with customers [line items]
Revenue from contracts with customers	279
Chemicals and Materials [member]
Disclosure of disaggregation of revenue from contracts with customers [line items]
Revenue from contracts with customers	243,014
Chemicals and Materials [member] | Japan [member]
Disclosure of disaggregation of revenue from contracts with customers [line items]
Revenue from contracts with customers	155,184
Chemicals and Materials [member] | Asia [Member]
Disclosure of disaggregation of revenue from contracts with customers [line items]
Revenue from contracts with customers	78,872
Chemicals and Materials [member] | Middle East [member]
Disclosure of disaggregation of revenue from contracts with customers [line items]
Revenue from contracts with customers	319
Chemicals and Materials [member] | Europe [Member]
Disclosure of disaggregation of revenue from contracts with customers [line items]
Revenue from contracts with customers	4,426
Chemicals and Materials [member] | North America [Member]
Disclosure of disaggregation of revenue from contracts with customers [line items]
Revenue from contracts with customers	4,055
Chemicals and Materials [member] | Central and South America [member]
Disclosure of disaggregation of revenue from contracts with customers [line items]
Revenue from contracts with customers	156
Chemicals and Materials [member] | Africa [Member]
Disclosure of disaggregation of revenue from contracts with customers [line items]
Revenue from contracts with customers	0
Chemicals and Materials [member] | Pacific [Member]
Disclosure of disaggregation of revenue from contracts with customers [line items]
Revenue from contracts with customers	0
System Solutions [member]
Disclosure of disaggregation of revenue from contracts with customers [line items]
Revenue from contracts with customers	204,952
System Solutions [member] | Japan [member]
Disclosure of disaggregation of revenue from contracts with customers [line items]
Revenue from contracts with customers	201,868
System Solutions [member] | Asia [Member]
Disclosure of disaggregation of revenue from contracts with customers [line items]
Revenue from contracts with customers	2,831
System Solutions [member] | Europe [Member]
Disclosure of disaggregation of revenue from contracts with customers [line items]
Revenue from contracts with customers	66
System Solutions [member] | North America [Member]
Disclosure of disaggregation of revenue from contracts with customers [line items]
Revenue from contracts with customers	151
System Solutions [member] | Central and South America [member]
Disclosure of disaggregation of revenue from contracts with customers [line items]
Revenue from contracts with customers	¥ 34

Revenue - Contract Balances (De

Revenue - Contract Balances (Detail) - JPY (¥) ¥ in Millions	Mar. 31, 2019	Apr. 01, 2018
Disclosure Of Changes In Contract Assets And Contract Liabilities [abstract]
Receivables	¥ 774,803	¥ 685,761
Contract assets	67,769	45,044
Contract liabilities	¥ 28,488	¥ 22,936

Revenue - Additional Informatio

Revenue - Additional Information (Detail) ¥ in Millions	12 Months Ended
	Mar. 31, 2019JPY (¥)
Disclosure of disaggregation of revenue from contracts with customers [abstract]
Amount included in the contract liabilities as of April 1, 2018 and recognized as revenue for the year ended March 31, 2019	¥ 20,099

Revenue - Transaction Price All

Revenue - Transaction Price Allocated to Remaining Performance Obligation (Detail) ¥ in Millions	Mar. 31, 2019JPY (¥)
Disclosure of transaction price allocated to remaining performance obligations [line items]
Transaction price allocated to the remaining performance obligation	¥ 461,872
Within 1 year [member]
Disclosure of transaction price allocated to remaining performance obligations [line items]
Transaction price allocated to the remaining performance obligation	259,610
Over 1 year [member]
Disclosure of transaction price allocated to remaining performance obligations [line items]
Transaction price allocated to the remaining performance obligation	202,262
Engineering and Construction [member]
Disclosure of transaction price allocated to remaining performance obligations [line items]
Transaction price allocated to the remaining performance obligation	355,351
Engineering and Construction [member] | Within 1 year [member]
Disclosure of transaction price allocated to remaining performance obligations [line items]
Transaction price allocated to the remaining performance obligation	184,782
Engineering and Construction [member] | Over 1 year [member]
Disclosure of transaction price allocated to remaining performance obligations [line items]
Transaction price allocated to the remaining performance obligation	170,569
System Solutions [member]
Disclosure of transaction price allocated to remaining performance obligations [line items]
Transaction price allocated to the remaining performance obligation	106,521
System Solutions [member] | Within 1 year [member]
Disclosure of transaction price allocated to remaining performance obligations [line items]
Transaction price allocated to the remaining performance obligation	74,828
System Solutions [member] | Over 1 year [member]
Disclosure of transaction price allocated to remaining performance obligations [line items]
Transaction price allocated to the remaining performance obligation	¥ 31,693

Selling, General and Administ_3

Selling, General and Administration Expenses - Components of Selling, General and Administrative Expenses (Detail) - JPY (¥) ¥ in Millions	12 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Mar. 31, 2017
Disclosure of selling general and administrative expenses [line items]
Retirement benefit costs	¥ 869,640	¥ 831,273	¥ 753,712
Research and development costs	72,043	74,071	70,100
Depreciation and amortization	408,616	366,565	330,912
Total	568,409	533,787	466,351
Selling general and administrative expenses [member]
Disclosure of selling general and administrative expenses [line items]
Transportation and storage	161,091	141,873	112,637
Salaries and bonuses	141,390	137,687	122,184
Retirement benefit costs	8,713	7,336	5,897
Research and development costs	58,621	61,019	54,912
Depreciation and amortization	8,693	10,064	7,138
Other	189,901	175,804	163,584
Total	¥ 568,409	¥ 533,787	¥ 466,351

Research and Development Cost_2

Research and Development Costs - Total Amounts of Research and Development Costs (Detail) - JPY (¥) ¥ in Millions	12 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Mar. 31, 2017
Expenses by nature [abstract]
Research and development costs	¥ 72,043	¥ 74,071	¥ 70,100

Other Operating Income and Ot_3

Other Operating Income and Other Operating Expenses - Other Operating Income (Detail) - JPY (¥) ¥ in Millions	12 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Mar. 31, 2017
Analysis of income and expense [abstract]
Dividends received	¥ 20,156	¥ 17,832	¥ 15,005
Foreign exchanges gains (net)	6,152
Other	76,296	73,689	47,102
Total	¥ 102,606	¥ 91,521	¥ 62,108

Other Operating Income and Ot_4

Other Operating Income and Other Operating Expenses - Other Operating Expenses (Detail) - JPY (¥) ¥ in Millions	12 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Mar. 31, 2017
Analysis of income and expense [abstract]
Foreign exchanges losses (net)		¥ 3,976	¥ 9,310
Impairment losses		18,075
Losses on disposal of fixed assets	¥ 27,665	30,540	32,322
Other	42,455	46,181	39,539
Total	¥ 70,120	¥ 98,773	¥ 81,171

Losses on natural disaster - Ad

Losses on natural disaster - Additional Information (Detail) ¥ in Millions	12 Months Ended
	Mar. 31, 2019JPY (¥)
Disclosure - Losses on natural disaster - Additional Information [Abstract]
Losses on natural disaster	¥ 22,349

Gains or Losses from Reorgani_2

Gains or Losses from Reorganization - Additional Information (Detail) - JPY (¥) ¥ in Millions	12 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Restructuring provision [abstract]
Impairment losses	¥ 16,882	¥ 18,075
Losses on withdrawal from businesses	17,443
Losses incurred to withdraw inactive facilities and other losses	¥ 15,154

Finance Income and Finance Co_3

Finance Income and Finance Costs - Financial Income (Detail) - JPY (¥) ¥ in Millions	12 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Mar. 31, 2017
Finance Income [line items]
Finance income	¥ 6,104	¥ 7,644	¥ 6,322
Interest income [member]
Finance Income [line items]
Finance income	6,028	5,710	6,241
Other Financial Income [member]
Finance Income [line items]
Finance income	¥ 76	¥ 1,933	¥ 81

Finance Income and Finance Co_4

Finance Income and Finance Costs - Financial Costs (Detail) - JPY (¥) ¥ in Millions	12 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Mar. 31, 2017
Finance Costs [line items]
Finance costs	¥ 22,445	¥ 24,584	¥ 21,586
Interest expense [member]
Finance Costs [line items]
Finance costs	19,133	21,339	19,292
Other Financial Costs [member]
Finance Costs [line items]
Finance costs	¥ 3,311	¥ 3,245	¥ 2,293

Impairment of Assets - Impairme

Impairment of Assets - Impairment Losses (Detail) - JPY (¥) ¥ in Millions	12 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Disclosure of impairment loss recognised or reversed for cash-generating unit [line items]
Impairment Loss	¥ 16,882	¥ 18,075
Adjustments [member]
Disclosure of impairment loss recognised or reversed for cash-generating unit [line items]
Impairment Loss		(234)
Steelmaking and Steel Fabrication [member]
Disclosure of impairment loss recognised or reversed for cash-generating unit [line items]
Impairment Loss	11,909	9,932
Engineering and Construction [member]
Disclosure of impairment loss recognised or reversed for cash-generating unit [line items]
Impairment Loss	¥ 4,972	2,472
Chemicals and Materials [member]
Disclosure of impairment loss recognised or reversed for cash-generating unit [line items]
Impairment Loss		3,334
System Solutions [member]
Disclosure of impairment loss recognised or reversed for cash-generating unit [line items]
Impairment Loss		¥ 2,570

Impairment of Assets - Addition

Impairment of Assets - Additional Information (Detail) - JPY (¥) ¥ in Millions	12 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Disclosure of impairment loss recognised or reversed for cash-generating unit [line items]
Impairment losses	¥ 16,882	¥ 18,075
Top of range [member]
Disclosure of impairment loss recognised or reversed for cash-generating unit [line items]
Future cash flows estimate cover	5 years
Steelmaking and Steel Fabrication [member]
Disclosure of impairment loss recognised or reversed for cash-generating unit [line items]
Impairment losses	¥ 11,909	9,932
Discounted cash flow method with the pre-tax discounted rate	8.00%
Steelmaking and Steel Fabrication [member] | Pipe Business [member]
Disclosure of impairment loss recognised or reversed for cash-generating unit [line items]
Impairment losses		8,505
Recoverable amount of assets		¥ 0
Steelmaking and Steel Fabrication [member] | Manufactures and Marketing of Railway Wheels and Axles [member]
Disclosure of impairment loss recognised or reversed for cash-generating unit [line items]
Impairment losses	¥ 5,990
Steelmaking and Steel Fabrication [member] | Investments accounted for using equity method [member]
Disclosure of impairment loss recognised or reversed for cash-generating unit [line items]
Impairment losses	¥ 5,919

Impairment of Assets - Impair_2

Impairment of Assets - Impairment Losses of Goodwill (Detail) - JPY (¥) ¥ in Millions	Mar. 31, 2019	Mar. 31, 2018
Disclosure of impairment loss recognised or reversed for cash-generating unit [line items]
Goodwill	¥ 52,803	¥ 42,263
Steelmaking and Steel Fabrication [member]
Disclosure of impairment loss recognised or reversed for cash-generating unit [line items]
Goodwill	44,477	28,596
Engineering and Construction [member]
Disclosure of impairment loss recognised or reversed for cash-generating unit [line items]
Goodwill	3,300	8,641
System Solutions [member]
Disclosure of impairment loss recognised or reversed for cash-generating unit [line items]
Goodwill	¥ 5,025	¥ 5,025

Other Comprehensive Income - Co

Other Comprehensive Income - Components of Other Comprehensive Income (Detail) - JPY (¥) ¥ in Millions	12 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Mar. 31, 2017
Items that will not be reclassified to profit or loss, incurred during the year
Changes in fair value of financial assets measured at fair value through other comprehensive income	¥ (138,361)	¥ 94,274	¥ 119,533
Remeasurements of defined benefit assets	(6,641)	29,253	33,791
Share of other comprehensive income of investments accounted for using the equity method	(2,953)	5,125	406
Subtotal	(147,956)	128,653	153,732
Items that will be reclassified to profit or loss, incurred during the year
Changes in fair value of cash flow hedges	6,155	(2,351)	5,404
Foreign exchange differences on translation of foreign operations	(42,391)	12,390	(28,332)
Share of other comprehensive income of investments accounted for using the equity method	(21,750)	(2,488)	8,008
Subtotal	(57,985)	7,550	(14,919)
Total	(205,942)	136,203	138,812
Items that will be reclassified to profit or loss, reclassification
Changes in fair value of cash flow hedges	(4,234)	4,678	8,533
Foreign exchange differences on translation of foreign operations	(111)	(215)	2,551
Share of other comprehensive income of investments accounted for using the equity method	62	(113)	1,854
Subtotal	(4,283)	4,349	12,939
Total	(4,283)	4,349	12,939
Items that will not be reclassified to profit or loss, before-tax
Changes in fair value of financial assets measured at fair value through other comprehensive income	(138,361)	94,274	119,533
Remeasurements of defined benefit assets	(6,641)	29,253	33,791
Share of other comprehensive income of investments accounted for using the equity method	(2,953)	5,125	406
Subtotal	(147,956)	128,653	153,732
Items that will be reclassified to profit or loss, before-tax
Changes in fair value of cash flow hedges	1,921	2,326	13,937
Foreign exchange differences on translation of foreign operations	(42,502)	12,174	(25,781)
Share of other comprehensive income of investments accounted for using the equity method	(21,687)	(2,602)	9,863
Subtotal	(62,269)	11,899	(1,980)
Total	(210,225)	140,552	151,751
Items that will not be reclassified to profit or loss, tax effect
Changes in fair value of financial assets measured at fair value through other comprehensive income	33,804	(29,051)	(33,263)
Remeasurements of defined benefit assets	3,109	(9,831)	(9,727)
Share of other comprehensive income of investments accounted for using the equity method	0	0	0
Subtotal	36,913	(38,883)	(42,991)
Items that will be reclassified to profit or loss, tax effect
Changes in fair value of cash flow hedges	(398)	(538)	(4,485)
Foreign exchange differences on translation of foreign operations	1,246	(1,582)	702
Share of other comprehensive income of investments accounted for using the equity method	0	0	0
Subtotal	847	(2,120)	(3,782)
Total	37,761	(41,003)	(46,774)
Items that will not be reclassified to profit or loss, net of tax
Changes in fair value of financial assets measured at fair value through other comprehensive income	(104,557)	65,222	86,269
Remeasurements of defined benefit assets	(3,531)	19,422	24,063
Share of other comprehensive income of investments accounted for using the equity method	(2,953)	5,125	406
Subtotal	(111,042)	89,770	110,740
Items that will be reclassified to profit or loss, net of tax
Changes in fair value of cash flow hedges	1,522	1,788	9,452
Foreign exchange differences on translation of foreign operations	(41,256)	10,592	(25,079)
Share of other comprehensive income of investments accounted for using the equity method	(21,687)	(2,602)	9,863
Subtotal	(61,421)	9,778	(5,763)
Total	¥ (172,464)	¥ 99,548	¥ 104,977

Earnings per Share - Summary of

Earnings per Share - Summary of Profit Attributable to Common Shares of the Parent (Detail) - JPY (¥) ¥ in Millions	12 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Mar. 31, 2017
Earnings per share [abstract]
Profit for the year attributable to owners of the parent	¥ 251,169	¥ 180,832	¥ 137,246
Profit for the year not attributable to ordinary equity holders of the parent	0	0	0
Profit for the year used to calculate basic earnings per share	¥ 251,169	¥ 180,832	¥ 137,246

Earnings per Share - Summary _2

Earnings per Share - Summary of Weighted Average Number of Ordinary Shares Outstanding (Detail) - shares	12 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Mar. 31, 2017
Earnings per share [abstract]
Weighted average number of ordinary shares outstanding	891,387,729	882,629,157	884,959,677

Financial Instruments - Schedul

Financial Instruments - Schedule of Key Management Indicators (Detail)	12 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Disclosure of detailed information about financial instruments [abstract]
ROE	7.90%	6.00%
D/E Ratio	0.73	0.69

Financial Instruments - Carryin

Financial Instruments - Carrying Amounts of Financial Instruments by Classification (Detail) - JPY (¥) ¥ in Millions	Mar. 31, 2019	Mar. 31, 2018	Mar. 31, 2017	Mar. 31, 2016
Financial liabilities
Trade and other payables	¥ 1,611,403	¥ 1,580,597
Bonds and borrowings	506,571	496,833
Other financial liabilities Derivatives	1,017	674
Bonds and borrowings	1,815,905	1,611,153
Other financial liabilities Derivatives	6,501	6,572
Other non-current liabilities	142,149	120,156
Financial assets
Cash and cash equivalents	163,176	142,869	¥ 123,929	¥ 121,183
Trade and other receivables	900,563	832,040
Other financial assets	16,915	19,178
Derivatives	4,071	6,827
Debt instruments	12,844	12,351
Other financial assets	812,668	1,007,627
Equity instruments	718,470	926,465
Derivatives	9,985	6,623
Debt instruments	84,211	74,538
Financial assets at amortised cost, class [member]
Financial assets
Cash and cash equivalents	163,176	142,869
Trade and other receivables	900,563	832,040
Other financial assets	12,844	12,351
Debt instruments	12,844	12,351
Other financial assets	84,211	74,538
Debt instruments	84,211	74,538
Financial assets at fair value through profit or loss, category [member]
Financial assets
Other financial assets	590	61
Derivatives	590	61
Financial assets at fair value through other comprehensive income, category [member]
Financial assets
Other financial assets	3,480	6,765
Derivatives	3,480	6,765
Other financial assets	728,456	933,088
Equity instruments	718,470	926,465
Derivatives	9,985	6,623
Financial liabilities at amortised cost, class [member]
Financial liabilities
Trade and other payables	1,611,403	1,580,597
Bonds and borrowings	506,571	496,833
Bonds and borrowings	1,815,905	1,611,153
Other non-current liabilities	142,149	120,156
Financial liabilities at fair value through profit or loss, category [member]
Financial liabilities
Other financial liabilities Derivatives	258	329
Financial Liabilities Measured At Fair Value through Other Comprehensive Income Category [member]
Financial liabilities
Other financial liabilities Derivatives	758	344
Other financial liabilities Derivatives	¥ 6,501	¥ 6,572

Financial Instruments - Additio

Financial Instruments - Additional Information (Detail) - JPY (¥) ¥ in Millions	12 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Disclosure of financial information [line items]
IFRS 15 impact on assets recognized	¥ 67,769
IAS 19 impact on liabilities recognized	24,085	¥ 22,971
Borrowings	¥ 2,369,231	2,157,755
Currency risk [member]
Disclosure of financial information [line items]
Impacts on profit before income taxes	1.00%
Interest rate risk [member]
Disclosure of financial information [line items]
Impacts on profit before income taxes	1.00%
Commitment Line Agreement [member]
Disclosure of financial information [line items]
Borrowings	¥ 0
Loan Facility Agreement [member]
Disclosure of financial information [line items]
Available credit balance	¥ 666,096	¥ 650,933

Financial Instruments - Financi

Financial Instruments - Financial Instruments Measured at Fair Value on a Recurring Basis (Detail) - At fair value [member] - JPY (¥) ¥ in Millions	Mar. 31, 2019	Mar. 31, 2018
Derivative Assets [member]
Financial assets
Fair value measured through profit or loss	¥ 590	¥ 61
Fair value measured through other comprehensive income	13,466	13,388
Derivative Assets [member] | Level 2 of fair value hierarchy [member]
Financial assets
Fair value measured through profit or loss	590	61
Fair value measured through other comprehensive income	13,466	13,388
Equity instruments [member]
Financial assets
Fair value measured through other comprehensive income	718,470	926,465
Equity instruments [member] | With quoted market price in an active market [member]
Financial assets
Fair value measured through other comprehensive income	638,768	847,645
Equity instruments [member] | Level 3 of fair value hierarchy [member]
Financial assets
Fair value measured through other comprehensive income	79,702	78,819
Derivative liabilities [member]
Financial liabilities
Fair value measured through profit or loss	258	329
Fair value measured through other comprehensive income	7,260	6,917
Derivative liabilities [member] | Level 2 of fair value hierarchy [member]
Financial liabilities
Fair value measured through profit or loss	258	329
Fair value measured through other comprehensive income	¥ 7,260	¥ 6,917

Financial Instruments - Sched_2

Financial Instruments - Schedule of Changes in Equity Instruments Measures at Level 3 (Detail) - At fair value [member] - Equity instruments [member] - Level 3 of fair value hierarchy [member] - JPY (¥) ¥ in Millions	12 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Disclosure of financial information [line items]
Balance at beginning of the year	¥ 78,819	¥ 83,237
Net changes in fair value	1,122	1,197
Acquisitions	116	54
Sale / settlements	(641)	(2,106)
Other	286	(3,562)
Balance at end of the year	¥ 79,702	¥ 78,819

Financial Instruments - Fair Va

Financial Instruments - Fair Value of Significant Equity Instruments Measured at FVOCI (Detail) - Equity instruments [member] - JPY (¥) ¥ in Millions	Mar. 31, 2019	Mar. 31, 2018
Toyota Motor Corporation [member]
Disclosure of financial information [line items]
Fair value measured through other comprehensive income	¥ 80,312	¥ 79,778
POSCO member]
Disclosure of financial information [line items]
Fair value measured through other comprehensive income	70,952	96,996
Suzuki Motor Corporation [member]
Disclosure of financial information [line items]
Fair value measured through other comprehensive income	38,006	44,462
Recruit Holdings [member]
Disclosure of financial information [line items]
Fair value measured through other comprehensive income	37,110
Central Japan Railway Company [member]
Disclosure of financial information [line items]
Fair value measured through other comprehensive income	¥ 30,633
SUMCO Corporation [member]
Disclosure of financial information [line items]
Fair value measured through other comprehensive income		64,783
Vallourec S.A. [member]
Disclosure of financial information [line items]
Fair value measured through other comprehensive income		¥ 37,466

Financial Instruments - Derecog

Financial Instruments - Derecognition of Financial Assets Measured at Fair Value (Detail) - JPY (¥) ¥ in Millions	12 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Disclosure of detailed information about financial instruments [abstract]
Fair value at the time of derecognition	¥ 83,726	¥ 37,532
Cumulative gains or losses on disposal (net of tax)	¥ 14,679	¥ 6,542

Financial Instruments - Dividen

Financial Instruments - Dividends Recognized for Equity Investments Measured at FVOCI (Detail) - JPY (¥) ¥ in Millions	12 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Disclosure of detailed information about financial instruments [abstract]
Investment derecognized in the reporting period	¥ 2,168	¥ 865
Investment held at the end of reporting period	17,988	16,967
Total	¥ 20,156	¥ 17,832

Financial Instruments - Fair _2

Financial Instruments - Fair value of Financial Assets and Liabilities Measured at Amortized Cost (Detail) - JPY (¥) ¥ in Millions	Mar. 31, 2019	Mar. 31, 2018
Financial assets
Debt instruments, current	¥ 12,844	¥ 12,351
Debt instruments, non current	84,211	74,538
Financial liabilities
Bonds and borrowings, current	506,571	496,833
Bonds and borrowings, non current	1,815,905	1,611,153
Financial Assets and Liabilities at Amortised Cost [member]
Financial assets
Debt instruments, current	12,844	12,351
Debt instruments, non current	84,211	74,538
Financial liabilities
Bonds and borrowings, current	506,571	496,833
Bonds and borrowings, non current	1,815,905	1,611,153
Financial Assets and Liabilities at Amortised Cost [member] | With quoted market price in an active market [member]
Financial assets
Debt instruments, current	9,498	1,233
Debt instruments, non current	11	23
Financial liabilities
Bonds and borrowings, current	60,386	86,080
Bonds and borrowings, non current	224,669	215,686
Financial Assets and Liabilities at Amortised Cost [member] | Level 2 of fair value hierarchy [member]
Financial assets
Debt instruments, current	0	3,103
Debt instruments, non current	7,512	5,497
Financial Assets and Liabilities at Amortised Cost [member] | Level 3 of fair value hierarchy [member]
Financial assets
Debt instruments, current	3,345	8,018
Debt instruments, non current	76,699	69,015
Financial liabilities
Bonds and borrowings, current	446,571	411,133
Bonds and borrowings, non current	¥ 1,618,043	¥ 1,415,613

Financial Instruments - Summary

Financial Instruments - Summary of Principal Foreign Currency Risk Exposures (Detail) - USD ($) $ in Millions	Mar. 31, 2019	Mar. 31, 2018
Disclosure of detailed information about financial instruments [abstract]
Net exposure (liability)	$ 78	$ (174)

Financial Instruments - Summa_2

Financial Instruments - Summary of Principal Foreign Currency Risk Exposures Impact on Profit Before Income Taxes (Detail) - JPY (¥) ¥ in Millions	12 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Interest rate risk [member]
Disclosure of financial information [line items]
Impacts on profit before income taxes	¥ (6,043)	¥ (5,787)
Currency risk [member]
Disclosure of financial information [line items]
Impacts on profit before income taxes	¥ (86)	¥ 185

Financial Instruments - Summa_3

Financial Instruments - Summary of Aging of Trade and Other Receivables (Detail) - JPY (¥) ¥ in Millions	Mar. 31, 2019	Mar. 31, 2018
Disclosure of financial information [line items]
Trade and other receivable	¥ 970,740	¥ 834,142
Current [member]
Disclosure of financial information [line items]
Trade and other receivable	964,845	831,985
Within Ninety Days [Member]
Disclosure of financial information [line items]
Trade and other receivable	4,991	1,684
Over Ninety Days and Within One Year [Member]
Disclosure of financial information [line items]
Trade and other receivable	729	363
Over 1 year [member]
Disclosure of financial information [line items]
Trade and other receivable	¥ 173	¥ 108

Financial Instruments - Sched_3

Financial Instruments - Schedule of Changes in Allowance for Doubtful Accounts (Detail) - JPY (¥) ¥ in Millions	12 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Disclosure of detailed information about financial instruments [abstract]
Balance at beginning of the year	¥ 5,878	¥ 5,854
Increase during the year	1,776	1,529
Decrease during the year	(696)	(1,513)
Other	183	7
Balance at end of the year	¥ 7,142	¥ 5,878

Financial Instruments - Sched_4

Financial Instruments - Schedule of Financial Liabilities by Contractual Maturity (Detail) - JPY (¥) ¥ in Millions	Mar. 31, 2019	Mar. 31, 2018
Disclosure of financial information [line items]
Trade and other payables	¥ 1,611,403	¥ 1,580,597
Borrowings	2,369,231	2,157,755
Gross carrying amount [member]
Disclosure of financial information [line items]
Trade and other payables	1,611,403	1,580,597
Borrowings	1,922,476	1,723,290
Bonds	280,000	295,696
Lease liabilities	46,754	49,768
Commercial paper	120,000	89,000
Derivatives	7,519	7,246
Total	3,988,154	3,745,600
Contractual Cash Flows [member]
Disclosure of financial information [line items]
Trade and other payables	1,611,403	1,580,597
Borrowings	1,922,476	1,723,290
Bonds	280,000	295,700
Lease liabilities	46,754	49,768
Commercial paper	120,000	89,000
Derivatives	7,019	8,080
Total	3,987,654	3,746,436
Within 1 year [member]
Disclosure of financial information [line items]
Trade and other payables	1,611,403	1,580,597
Borrowings	326,571	322,133
Bonds	60,000	85,700
Lease liabilities	8,783	8,550
Commercial paper	120,000	89,000
Derivatives	2,656	2,279
Total	2,129,414	2,088,260
Over 1 but less than 5 years [member]
Disclosure of financial information [line items]
Borrowings	657,235	584,131
Bonds	100,000	140,000
Lease liabilities	21,034	22,582
Derivatives	4,363	5,478
Total	782,633	752,192
Over 5 years [member]
Disclosure of financial information [line items]
Borrowings	938,670	817,024
Bonds	120,000	70,000
Lease liabilities	16,936	18,635
Derivatives		323
Total	¥ 1,075,606	¥ 905,983

Financial Instruments - Sched_5

Financial Instruments - Schedule of Derivative Assets and Liabilities Designated as Hedging Instruments (Detail) - JPY (¥) ¥ in Millions	12 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Disclosure of financial information [line items]
Total notional amount	¥ 551,957	¥ 605,695
Settlement in excess of one year	326,949	335,425
Carrying amount (Fair value), assets	13,466	13,388
Carrying amount (Fair value), liabilities	7,260	6,917
Foreign Exchange Forward Contract [member] | Cash flow hedges [member]
Disclosure of financial information [line items]
Total notional amount	217,369	246,189
Settlement in excess of one year	6,762	9,113
Carrying amount (Fair value), assets	1,752	1,069
Carrying amount (Fair value), liabilities	750	303
Interest rate swap contract [member] | Cash flow hedges [member]
Disclosure of financial information [line items]
Total notional amount	264,704	275,939
Settlement in excess of one year	252,848	258,741
Carrying amount (Fair value), assets	730	601
Carrying amount (Fair value), liabilities	6,509	6,613
Currency swap contract [member] | Cash flow hedges [member]
Disclosure of financial information [line items]
Total notional amount	67,353	83,244
Settlement in excess of one year	66,280	67,353
Carrying amount (Fair value), assets	9,462	11,665
Commodity Swaps [member] | Cash flow hedges [member]
Disclosure of financial information [line items]
Total notional amount	2,529	321
Settlement in excess of one year	1,058	217
Carrying amount (Fair value), assets	¥ 1,519	¥ 52

Financial Instruments - Summa_4

Financial Instruments - Summary of Derivative Assets and Liabilities not Designated as Hedges (Detail) - JPY (¥) ¥ in Millions	Mar. 31, 2019	Mar. 31, 2018
Disclosure of financial information [line items]
Derivative financial assets	¥ 590	¥ 124
Derivative financial liabilities	258	392
Foreign Exchange Forward Contract [member]
Disclosure of financial information [line items]
Derivative financial assets	492	4
Derivative financial liabilities	248	381
Interest rate swap contract [member]
Disclosure of financial information [line items]
Derivative financial assets		2
Currency swap contract [member]
Disclosure of financial information [line items]
Derivative financial assets	97	118
Derivative financial liabilities	¥ 10	¥ 11

Financial Instruments - Summa_5

Financial Instruments - Summary of Changes in Fair Value of Cash Flow Hedges (Detail) - JPY (¥) ¥ in Millions	12 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Disclosure of detailed information about hedges [line items]
Beginning of the year	¥ (5,080)	¥ (7,407)
Changes in fair value of cash flow hedge recognized in the other comprehensive income	6,155	(2,351)
Amount transferred to profit or loss from other components of equity as a reclassification adjustment	(4,234)	4,678
The account in which the reclassification adjustment to End of the profit or loss year is recognized	(3,159)	(5,080)
Currency risk [member]
Disclosure of detailed information about hedges [line items]
Beginning of the year	426	(682)
Changes in fair value of cash flow hedge recognized in the other comprehensive income	4,407	(3,626)
Amount transferred to profit or loss from other components of equity as a reclassification adjustment	(4,186)	4,734
The account in which the reclassification adjustment to End of the profit or loss year is recognized	646	426
Interest rate risk [member]
Disclosure of detailed information about hedges [line items]
Beginning of the year	(5,559)	(6,762)
Changes in fair value of cash flow hedge recognized in the other comprehensive income	228	1,222
Amount transferred to profit or loss from other components of equity as a reclassification adjustment	5	(18)
The account in which the reclassification adjustment to End of the profit or loss year is recognized	(5,326)	(5,559)
Other price risk [member]
Disclosure of detailed information about hedges [line items]
Beginning of the year	52	37
Changes in fair value of cash flow hedge recognized in the other comprehensive income	1,519	52
Amount transferred to profit or loss from other components of equity as a reclassification adjustment	(52)	(37)
The account in which the reclassification adjustment to End of the profit or loss year is recognized	¥ 1,519	¥ 52

Related Party Disclosures - Sum

Related Party Disclosures - Summary of Transactions with Related Parties (Detail) - JPY (¥) ¥ in Millions	12 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Disclosure of transactions between related parties [abstract]
Sells of steel products	¥ 1,170,241	¥ 849,244
Account trade and other receivables	¥ 46,251	¥ 39,236

Related Parties - Schedule of K

Related Parties - Schedule of Key Management Personnel Compensation (Detail) - JPY (¥) ¥ in Millions	12 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Mar. 31, 2017
Disclosure of transactions between related parties [abstract]
Salary	¥ 935	¥ 857	¥ 964

Commitments - Significant Commi

Commitments - Significant Commitments Related to the Acquisition of Assets (Detail) - JPY (¥) ¥ in Millions	Mar. 31, 2019	Mar. 31, 2018
Disclosure Of Capital Expenditures Commitments [abstract]
Contractual commitments related to acquisition of property, plant and equipment and intangible assets	¥ 393,230	¥ 316,808

Loan Guarantees - Guarantees fo

Loan Guarantees - Guarantees for Bank Loans of its Joint Ventures and Associates Which Would Require the Group to Repay the Loan in the Event of Default (Detail) - JPY (¥) ¥ in Millions	Mar. 31, 2019	Mar. 31, 2018
Disclosure Of Guarantees [abstract]
Guarantees for the bank loans of joint ventures and associates	¥ 62,506	¥ 82,721