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 | — | 
                                                11,676,018,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                25,070,067,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                10,855,682,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Ordinary profit (loss) | — | 
                                                138,564,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,720,894,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                329,248,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Net assets | 
                                                20,254,228,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                20,616,433,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                19,535,455,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Total assets | 
                                                28,050,919,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                29,618,535,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                27,671,084,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Basic earnings (loss) per share | — | 
                                                12.93
                                                
                                             | 
                                                159.93
                                                
                                             | — | — | 
                                                29.20
                                                
                                             | 
| Diluted earnings per share | — |  |  | — | — |  | 
| Equity-to-asset ratio | 
                                                0.722
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                0.696
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.706
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
| Net cash provided by (used in) operating activities | — | 
                                                -2,611,702,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                3,514,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                733,449,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Net cash provided by (used in) investing activities | — | 
                                                -18,789,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -263,904,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -508,360,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Net cash provided by (used in) financing activities | — | 
                                                866,174,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -371,544,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -131,418,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Cash and cash equivalents | 
                                                3,594,637,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                5,359,860,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                6,085,275,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — |