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 | — | 
                                                5,794,474,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                10,045,586,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                4,648,104,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Ordinary profit (loss) | — | 
                                                91,194,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -4,114,510,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -4,448,383,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Net assets | 
                                                33,464,339,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                37,259,391,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                32,300,801,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Total assets | 
                                                43,159,575,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                46,838,448,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                40,372,113,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Basic earnings (loss) per share | — | 
                                                18.05
                                                
                                             | 
                                                -169.82
                                                
                                             | — | — | 
                                                -189.88
                                                
                                             | 
| Diluted earnings per share | — | 
                                                18.02
                                                
                                             |  | — | — |  | 
| Equity-to-asset ratio | 
                                                0.774
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                0.793
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.797
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
| Net cash provided by (used in) operating activities | — | 
                                                -1,155,400,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                2,509,798,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                3,816,820,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Net cash provided by (used in) investing activities | — | 
                                                -124,428,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -3,562,671,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -3,495,276,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Net cash provided by (used in) financing activities | — | 
                                                918,372,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -385,206,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -1,385,180,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Cash and cash equivalents | 
                                                1,156,755,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                1,519,890,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,892,432,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — |