Key Financial Data Of Group
| Concept | 2024-04-01 to 2024-09-30 | As at 2024-09-30 | As at 2024-03-31 | 2023-04-01 to 2024-03-31 | 2023-04-01 to 2023-09-30 | As at 2023-09-30 | 
|---|---|---|---|---|---|---|
| Key financial data of group | ||||||
| Business results of group | ||||||
| Net sales | 
                                                2,679,550,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                5,839,861,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                2,843,858,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Ordinary profit (loss) | 
                                                -91,324,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -28,092,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -74,347,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Net assets | — | 
                                                344,183,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                451,918,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                508,853,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Total assets | — | 
                                                1,977,172,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                2,005,845,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                2,188,092,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Basic earnings (loss) per share | 
                                                -21.56
                                                
                                             | — | — | 
                                                -31.78
                                                
                                             | 
                                                -20.39
                                                
                                             | — | 
| Diluted earnings per share |  | — | — |  |  | — | 
| Equity-to-asset ratio | — | 
                                                0.174
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.225
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                0.233
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
| Net cash provided by (used in) operating activities | 
                                                -99,900,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -25,414,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -13,212,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Net cash provided by (used in) investing activities | 
                                                -76,459,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -14,346,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -41,345,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Net cash provided by (used in) financing activities | 
                                                54,396,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -69,391,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -36,383,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Cash and cash equivalents | — | 
                                                144,195,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                266,177,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                284,387,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             |