Key Financial Data Of Reporting Company
| Concept | 2023-04-01 to 2023-12-31 | As at 2023-12-31 | 2023-10-01 to 2023-12-31 | As at 2023-03-31 | 2022-04-01 to 2023-03-31 | As at 2022-12-31 | 2022-04-01 to 2022-12-31 | 2022-10-01 to 2022-12-31 | 
|---|---|---|---|---|---|---|---|---|
| Key financial data of reporting company | ||||||||
| Business results of reporting company | ||||||||
| Net sales | 
                                                24,097,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                31,280,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                23,170,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Ordinary profit (loss) | 
                                                889,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                1,044,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                929,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Net assets | — | 
                                                22,188,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                21,713,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                21,510,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Total assets | — | 
                                                42,333,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                42,006,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                41,406,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Basic earnings (loss) per share | 
                                                126.69
                                                
                                             | — | 
                                                50.28
                                                
                                             | — | 
                                                140.87
                                                
                                             | — | 
                                                128.08
                                                
                                             | 
                                                57.56
                                                
                                             | 
| Diluted earnings per share |  | — | — | — |  | — |  | — | 
| Equity-to-asset ratio | — | 
                                                0.524
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                0.517
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                0.520
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — |