Key Financial Data Of Group
| Concept | 
                                    
                                        As at 2024-02-29  | 
                            
                                
                                    
                                        2023-06-01 to 2024-02-29  | 
                            
                                
                                    
                                        2023-12-01 to 2024-02-29  | 
                            
                                
                                    
                                        As at 2023-05-31  | 
                            
                                
                                    
                                        2022-06-01 to 2023-05-31  | 
                            
                                
                                    
                                        As at 2023-02-28  | 
                            
                                
                                    
                                        2022-12-01 to 2023-02-28  | 
                            
                                
                                    
                                        2022-06-01 to 2023-02-28  | 
                            
                        
|---|---|---|---|---|---|---|---|---|
| Key financial data of group | ||||||||
| Business results of group | ||||||||
| Net sales | — | 
                                        
                                             
                                                23,384,833,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    — | — | 
                                        
                                             
                                                29,321,724,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    — | — | 
                                        
                                             
                                                21,453,664,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             
                                        
                                     | 
                                
                            
| Ordinary profit (loss) | — | 
                                        
                                             
                                                852,174,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    — | — | 
                                        
                                             
                                                1,105,486,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    — | — | 
                                        
                                             
                                                808,626,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             
                                        
                                     | 
                                
                            
| Net assets | 
                                        
                                             
                                                14,757,060,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    — | — | 
                                        
                                             
                                                13,977,541,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    — | 
                                        
                                             
                                                13,619,959,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    — | — | 
| Total assets | 
                                        
                                             
                                                24,258,670,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    — | — | 
                                        
                                             
                                                23,213,983,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    — | 
                                        
                                             
                                                22,415,822,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    — | — | 
| Basic earnings (loss) per share | — | 
                                        
                                             
                                                141.32
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                36.18
                                                
                                             
                                        
                                     | 
                                
                                    — | 
                                        
                                             
                                                205.86
                                                
                                             
                                        
                                     | 
                                
                                    — | 
                                        
                                             
                                                39.51
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                137.53
                                                
                                             
                                        
                                     | 
                                
                            
| Diluted earnings per share | — | 
                                        
                                             | 
                                
                                    — | — | 
                                        
                                             | 
                                
                                    — | — | 
                                        
                                             | 
                                
                            
| Equity-to-asset ratio | 
                                        
                                             
                                                0.608
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    — | — | 
                                        
                                             
                                                0.602
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    — | 
                                        
                                             
                                                0.608
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    — | — |