Consolidated Statement Of Comprehensive Income
| Concept | 
                                    
                                        2023-10-01 to 2024-09-30  | 
                            
                                
                                    
                                        2023-10-01 to 2024-09-30  | 
                            
                                
                                    
                                        2023-10-01 to 2024-09-30  | 
                            
                                
                                    
                                        2023-10-01 to 2024-09-30  | 
                            
                                
                                    
                                        2023-10-01 to 2024-09-30  | 
                            
                                
                                    
                                        2022-10-01 to 2023-09-30  | 
                            
                                
                                    
                                        2022-10-01 to 2023-09-30  | 
                            
                                
                                    
                                        2022-10-01 to 2023-09-30  | 
                            
                                
                                    
                                        2022-10-01 to 2023-09-30  | 
                            
                                
                                    
                                        2022-10-01 to 2023-09-30  | 
                            
                        
|---|---|---|---|---|---|---|---|---|---|---|
| Consolidated statement of comprehensive income | ||||||||||
| Statement of comprehensive income | ||||||||||
| Profit (loss) | 
                                        
                                             
                                                270,648,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                244,192,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                270,648,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                270,648,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                270,648,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                -1,014,843,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                -1,014,843,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                -1,014,843,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                -1,042,023,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                -1,014,843,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             
                                        
                                     | 
                                
                            
| Other comprehensive income | ||||||||||
| Valuation difference on available-for-sale securities | — | 
                                        
                                             
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    — | — | — | — | — | — | 
                                        
                                             
                                                -145,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    — | 
| Other comprehensive income | — | 
                                        
                                             
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    — | — | — | — | — | — | 
                                        
                                             
                                                -145,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    — | 
| Comprehensive income | — | 
                                        
                                             
                                                244,192,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    — | — | — | — | — | — | 
                                        
                                             
                                                -1,042,169,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    — | 
| Comprehensive income attributable to | ||||||||||
| Comprehensive income attributable to owners of parent | — | 
                                        
                                             
                                                244,192,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    — | — | — | — | — | — | 
                                        
                                             
                                                -1,042,169,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    — |