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 | — | 
                                                14,093,530,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                25,950,897,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                13,114,139,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Ordinary profit (loss) | — | 
                                                2,644,819,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                3,175,847,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                1,941,111,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Net assets | 
                                                62,691,339,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                60,765,822,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                60,267,247,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Total assets | 
                                                111,937,726,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                110,461,725,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                108,173,558,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Basic earnings (loss) per share | — | 
                                                34.80
                                                
                                             | 
                                                40.27
                                                
                                             | — | — | 
                                                24.77
                                                
                                             | 
| Diluted earnings per share | — | 
                                                34.78
                                                
                                             | 
                                                40.23
                                                
                                             | — | — | 
                                                24.75
                                                
                                             | 
| Equity-to-asset ratio | 
                                                0.535
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                0.526
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.533
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
| Net cash provided by (used in) operating activities | — | 
                                                4,363,997,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                784,580,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -977,049,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Net cash provided by (used in) investing activities | — | 
                                                -3,148,284,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -3,831,011,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -2,864,202,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Net cash provided by (used in) financing activities | — | 
                                                -2,079,416,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                5,101,096,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                3,326,226,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Cash and cash equivalents | 
                                                10,151,141,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                10,849,304,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                8,276,396,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — |