Key Financial Data Of Reporting Company
| Concept | 2024-01-01 to 2024-03-31 | As at 2024-03-31 | 2023-10-01 to 2024-03-31 | As at 2023-09-30 | 2022-10-01 to 2023-09-30 | 2023-01-01 to 2023-03-31 | As at 2023-03-31 | 2022-10-01 to 2023-03-31 | 
|---|---|---|---|---|---|---|---|---|
| Key financial data of reporting company | ||||||||
| Business results of reporting company | ||||||||
| Net sales | — | — | 
                                                46,160,559,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                86,085,923,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                44,057,131,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Ordinary profit (loss) | — | — | 
                                                1,720,860,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                2,068,394,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                1,514,817,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Net assets | — | 
                                                25,001,041,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                24,179,517,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                23,904,644,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Total assets | — | 
                                                45,255,702,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                44,002,545,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                44,273,983,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Basic earnings (loss) per share | 
                                                51.98
                                                
                                             | — | 
                                                93.25
                                                
                                             | — | 
                                                110.16
                                                
                                             | 
                                                52.07
                                                
                                             | — | 
                                                79.69
                                                
                                             | 
| Diluted earnings per share | — | — |  | — |  | — | — |  | 
| Equity-to-asset ratio | — | 
                                                0.552
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                0.550
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                0.540
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
| Net cash provided by (used in) operating activities | — | — | 
                                                -549,366,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                1,677,487,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -303,882,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Net cash provided by (used in) investing activities | — | — | 
                                                -187,310,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -2,876,869,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -1,700,219,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Net cash provided by (used in) financing activities | — | — | 
                                                409,177,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -811,465,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                323,463,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Cash and cash equivalents | — | 
                                                10,079,165,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                10,166,176,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                10,496,385,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — |