Key Financial Data Of Reporting Company
| 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 reporting company | ||||||
| Business results of reporting company | ||||||
| Net sales | — | 
                                                8,820,511,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                20,429,304,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                9,321,720,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Ordinary profit (loss) | — | 
                                                -904,568,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                331,604,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -434,806,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Net assets | 
                                                3,886,622,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                4,531,959,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                3,458,773,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Total assets | 
                                                20,366,142,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                20,107,721,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                19,185,829,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Basic earnings (loss) per share | — | 
                                                -118.48
                                                
                                             | 
                                                114.13
                                                
                                             | — | — | 
                                                -81.27
                                                
                                             | 
| Diluted earnings per share | — |  |  | — | — |  | 
| Equity-to-asset ratio | 
                                                0.191
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                0.225
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.180
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
| Net cash provided by (used in) operating activities | — | 
                                                -88,872,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                699,097,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                320,608,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Net cash provided by (used in) investing activities | — | 
                                                -634,386,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -687,756,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -218,746,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Net cash provided by (used in) financing activities | — | 
                                                265,871,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                50,323,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -67,251,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Cash and cash equivalents | 
                                                994,382,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                1,361,969,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,336,401,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — |