| Cover | Apr. 26, 2023 |
| Cover [Abstract] | |
| Document Type | 8-K |
| Amendment Flag | false |
| Document Period End Date | Apr. 26, 2023 |
| Entity File Number | 033-17773-NY |
| Entity Registrant Name | ROCKETFUEL BLOCKCHAIN, INC. |
| Entity Central Index Key | 0000823546 |
| Entity Tax Identification Number | 90-1188745 |
| Entity Incorporation, State or Country Code | NV |
| Entity Address, Address Line One | 3651 Lindell Road |
| Entity Address, Address Line Two | Suite D565 |
| Entity Address, City or Town | Las Vegas |
| Entity Address, State or Province | NV |
| Entity Address, Postal Zip Code | 89103 |
| City Area Code | (424) |
| Local Phone Number | 256-8560 |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Entity Emerging Growth Company | false |
