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 | — | 
                                                11,997,515,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                18,867,885,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                7,647,657,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Ordinary profit (loss) | — | 
                                                3,899,721,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                6,265,098,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                2,232,068,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Profit (loss) attributable to owners of parent | — | 
                                                2,669,294,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                3,851,491,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                1,599,525,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Comprehensive income | — | 
                                                2,767,339,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                4,459,845,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                2,064,568,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Net assets | 
                                                19,915,075,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                17,735,761,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                15,810,904,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Total assets | 
                                                26,653,314,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                25,828,326,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                20,991,110,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Basic earnings (loss) per share | — | 
                                                226.97
                                                
                                             | 
                                                327.49
                                                
                                             | — | — | 
                                                136.01
                                                
                                             | 
| Diluted earnings per share | — |  |  | — | — |  | 
| Equity-to-asset ratio | 
                                                0.747
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                0.687
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.753
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
| Net cash provided by (used in) operating activities | — | 
                                                3,500,032,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                3,281,993,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                1,026,196,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Net cash provided by (used in) investing activities | — | 
                                                -1,428,261,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -194,810,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -12,026,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Net cash provided by (used in) financing activities | — | 
                                                -744,860,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -213,343,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -653,583,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Cash and cash equivalents | 
                                                10,493,716,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                9,373,250,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                6,777,072,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — |