v3.25.2
Crypto assets held - Changes in Crypto Assets Held (Details) - JPY (¥)
¥ in Millions
 12 Months Ended
Mar. 31, 2025
Mar. 31, 2024
Reconciliation Of Changes In Crypto Assets [Abstract]    
Crypto assets held (non-current assets), beginning balance [1] ¥ 0 ¥ 43
Additions (by business combination) 21  
Additions (not by business combination) 458 330
Disposals (435) (374)
Crypto assets held (non-current assets), ending balance 43 0 [1]
Cryptocurrency    
Reconciliation Of Changes In Crypto Assets [Abstract]    
Crypto assets held (non-current assets), beginning balance 0 24
Additions (by business combination) 21  
Additions (not by business combination) 458 330
Disposals (435) (354)
Crypto assets held (non-current assets), ending balance 43 0
NFT    
Reconciliation Of Changes In Crypto Assets [Abstract]    
Crypto assets held (non-current assets), beginning balance 0 19
Additions (by business combination) 0  
Additions (not by business combination) 0 0
Disposals 0 (19)
Crypto assets held (non-current assets), ending balance ¥ 0 ¥ 0
[1] The comparative information is restated due to change in accounting policy. See Note 2 (5) “Changes in