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 | 
                                                1,788,362,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                2,867,469,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                2,081,729,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Ordinary profit (loss) | 
                                                -417,977,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                227,650,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                124,174,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Net assets | — | 
                                                782,504,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                1,527,201,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                1,447,160,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Total assets | — | 
                                                2,456,948,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                2,559,945,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                2,415,863,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Basic earnings (loss) per share | 
                                                -129.14
                                                
                                             | — | 
                                                -19.44
                                                
                                             | — | 
                                                26.82
                                                
                                             | — | 
                                                12.22
                                                
                                             | 
                                                9.11
                                                
                                             | 
| Diluted earnings per share |  | — | — | — |  | — |  | — | 
| Equity-to-asset ratio | — | 
                                                0.316
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                0.594
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                0.596
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — |