Shareholdings
| Concept | As at 2025-03-31 | 2024-04-01 to 2025-03-31 | As at 2024-03-31 | 
|---|---|---|---|
| Shareholdings | |||
| Reporting company | |||
| Investment shares held for pure investment | |||
| Shares not listed | |||
| Number of issues | 
                                                
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
| Carrying amount | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Total of dividends received | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Total of gain (loss) on sale | — | 
                                                1,020,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Total of valuation gain (loss) | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Shares other than those not listed | |||
| Number of issues | 
                                                1
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                2
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
| Carrying amount | 
                                                22,653,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                23,149,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Total of dividends received | — | 
                                                993,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Total of gain (loss) on sale | — | 
                                                798,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Total of valuation gain (loss) | — | 
                                                12,381,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — |