Key Financial Data Of Group
| 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 group | ||||||
| Business results of group | ||||||
| Net sales | — | 
                                                5,808,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                11,090,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                5,345,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Ordinary profit (loss) | — | 
                                                1,408,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                2,785,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                1,247,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Profit (loss) attributable to owners of parent | — | 
                                                949,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,858,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                833,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Comprehensive income | — | 
                                                843,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                2,559,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                1,189,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Net assets | 
                                                12,206,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                12,230,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                11,284,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Total assets | 
                                                16,713,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                16,710,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                15,684,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Basic earnings (loss) per share | — | 
                                                22.54
                                                
                                             | 
                                                43.86
                                                
                                             | — | — | 
                                                19.67
                                                
                                             | 
| Diluted earnings per share | — |  |  | — | — |  | 
| Equity-to-asset ratio | 
                                                0.730
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                0.732
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.719
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
| Net cash provided by (used in) operating activities | — | 
                                                1,372,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                2,982,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                1,344,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Net cash provided by (used in) investing activities | — | 
                                                -1,646,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -553,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -400,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Net cash provided by (used in) financing activities | — | 
                                                -1,296,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -1,749,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -902,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Cash and cash equivalents | 
                                                5,381,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                6,952,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                6,314,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — |