Shareholdings
| Concept | As at 2023-09-30 | As at 2022-09-30 | 
|---|---|---|
| Shareholdings | ||
| Reporting company | ||
| Investment shares held for pure investment | ||
| Shares not listed | ||
| Number of issues | 
                                                
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
| Carrying amount | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Shares other than those not listed | ||
| Number of issues | 
                                                1
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                1
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
| Carrying amount | 
                                                124,260,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                102,800,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             |