Key Financial Data Of Reporting Company
| Concept | 2024-10-01 to 2025-03-31 | As at 2025-03-31 | As at 2024-09-30 | 2023-10-01 to 2024-09-30 | 2023-10-01 to 2024-03-31 | As at 2024-03-31 | 
|---|---|---|---|---|---|---|
| Key financial data of reporting company | ||||||
| Business results of reporting company | ||||||
| Net sales | 
                                                24,575,666,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                40,270,804,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                24,612,932,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Ordinary profit (loss) | 
                                                3,678,113,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                3,039,548,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                4,469,310,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Net assets | — | 
                                                23,009,296,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                21,207,257,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                22,357,768,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Total assets | — | 
                                                48,335,618,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                36,413,653,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                45,293,397,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Basic earnings (loss) per share | 
                                                133.65
                                                
                                             | — | — | 
                                                104.73
                                                
                                             | 
                                                164.23
                                                
                                             | — | 
| Diluted earnings per share |  | — | — |  |  | — | 
| Equity-to-asset ratio | — | 
                                                0.470
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.575
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                0.488
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
| Net cash provided by (used in) operating activities | 
                                                -9,555,254,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                594,119,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -7,295,601,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Net cash provided by (used in) investing activities | 
                                                -471,769,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -2,178,474,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -1,080,102,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Net cash provided by (used in) financing activities | 
                                                8,674,170,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                102,576,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                6,422,474,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Cash and cash equivalents | — | 
                                                5,347,494,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                6,697,584,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                6,201,600,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             |