Financial risk management - Narrative (Details) - JPY (¥) ¥ in Millions |
12 Months Ended | |
|---|---|---|
Mar. 31, 2026 |
Mar. 31, 2025 |
|
| Disclosure of credit risk exposure [line items] | ||
| Balance of executed borrowed commitment line | ¥ 2,758 | ¥ 751 |
| Crypto-Asset Service Provider (CASP) | ||
| Disclosure of credit risk exposure [line items] | ||
| Fixed overhead costs, percent | 25.00% | |
| Payment Institution (PI) Licenses | ||
| Disclosure of credit risk exposure [line items] | ||
| Fixed overhead costs, percent | 10.00% |