Employees
| Concept | As at 2024-09-30 | As at 2023-09-30 | As at 2022-09-30 | As at 2021-09-30 | As at 2020-09-30 | 
|---|---|---|---|---|---|
| Employees | |||||
| Information about reporting company | |||||
| Information about employees of reporting company | |||||
| Number of employees | 
                                                15
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                13
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                12
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                11
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                9
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
| Average age (Years) | 
                                                51.3
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | — | 
| Average length of service (Years) | 
                                                1.8
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | — | 
| Average annual salary | 
                                                5,041,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — |