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 | 
                                                23,069,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                31,559,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                24,015,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Ordinary profit (loss) | 
                                                125,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                58,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                549,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Net assets | — | 
                                                18,744,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                18,534,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                19,171,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Total assets | — | 
                                                50,943,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                48,571,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                50,035,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Basic earnings (loss) per share | 
                                                28.89
                                                
                                             | — | 
                                                20.17
                                                
                                             | — | 
                                                94.07
                                                
                                             | — | 
                                                189.62
                                                
                                             | 
                                                -58.82
                                                
                                             | 
| Diluted earnings per share |  | — | — | — |  | — |  | — | 
| Equity-to-asset ratio | — | 
                                                0.368
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                0.381
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                0.383
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — |