Key Financial Data Of Group
| Concept | As at 2024-09-30 | 2024-04-01 to 2024-09-30 | 2023-04-01 to 2024-03-31 | As at 2024-03-31 | As at 2023-09-30 | 2023-04-01 to 2023-09-30 | 
|---|---|---|---|---|---|---|
| Key financial data of group | ||||||
| Business results of group | ||||||
| Net sales | — | 
                                                6,576,899,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                13,861,882,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                6,355,928,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Ordinary profit (loss) | — | 
                                                -105,695,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                302,399,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                163,702,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Profit (loss) attributable to owners of parent | — | 
                                                -111,032,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                258,961,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                99,586,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Comprehensive income | — | 
                                                -111,032,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                258,961,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                99,586,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Net assets | 
                                                2,347,247,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                2,447,043,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                2,309,748,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Total assets | 
                                                7,613,284,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                7,421,698,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                7,003,908,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Basic earnings (loss) per share | — | 
                                                -18.86
                                                
                                             | 
                                                44.35
                                                
                                             | — | — | 
                                                17.10
                                                
                                             | 
| Diluted earnings per share | — |  | 
                                                43.33
                                                
                                             | — | — | 
                                                16.67
                                                
                                             | 
| Equity-to-asset ratio | 
                                                0.308
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                0.330
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.330
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
| Net cash provided by (used in) operating activities | — | 
                                                -308,617,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -609,174,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -1,043,347,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Net cash provided by (used in) investing activities | — | 
                                                -356,606,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -356,305,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -182,580,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Net cash provided by (used in) financing activities | — | 
                                                603,006,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                376,176,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                655,668,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Cash and cash equivalents | 
                                                2,070,695,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                2,132,912,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                2,127,899,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — |