Key Financial Data Of Group
| 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 group | ||||||||
| Business results of group | ||||||||
| Net sales | 
                                                116,021,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                161,881,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                119,899,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Ordinary profit (loss) | 
                                                6,375,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                10,994,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                7,806,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Profit (loss) attributable to owners of parent | 
                                                -22,141,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                2,273,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                2,053,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Comprehensive income | 
                                                -19,620,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                5,943,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                6,376,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Net assets | — | 
                                                47,658,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                50,678,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                51,090,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Total assets | — | 
                                                175,243,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                162,741,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                164,479,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Basic earnings (loss) per share | 
                                                -1,081.87
                                                
                                             | — | 
                                                30.69
                                                
                                             | — | 
                                                112.09
                                                
                                             | — | 
                                                101.24
                                                
                                             | 
                                                126.59
                                                
                                             | 
| Diluted earnings per share |  | — | — | — |  | — |  | — | 
| Equity-to-asset ratio | — | 
                                                0.269
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                0.309
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                0.308
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — |