Key Financial Data Of Group
| Concept | 2024-01-01 to 2024-06-30 | As at 2024-06-30 | 2023-01-01 to 2023-12-31 | As at 2023-12-31 | 2023-01-01 to 2023-06-30 | As at 2023-06-30 | 
|---|---|---|---|---|---|---|
| Key financial data of group | ||||||
| Business results of group | ||||||
| Net sales | 
                                                10,318,822,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                21,242,751,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                10,620,051,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Ordinary profit (loss) | 
                                                971,535,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                1,515,898,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                839,959,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Profit (loss) attributable to owners of parent | 
                                                615,162,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                966,355,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                535,548,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Comprehensive income | 
                                                1,290,243,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                1,300,884,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                903,272,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Net assets | — | 
                                                23,237,241,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                22,440,482,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                22,893,241,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Total assets | — | 
                                                35,300,696,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                32,451,056,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                32,582,644,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Basic earnings (loss) per share | 
                                                33.58
                                                
                                             | — | 
                                                52.76
                                                
                                             | — | 
                                                29.24
                                                
                                             | — | 
| Diluted earnings per share | 
                                                33.50
                                                
                                             | — | 
                                                52.63
                                                
                                             | — | 
                                                29.17
                                                
                                             | — | 
| Equity-to-asset ratio | — | 
                                                0.658
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                0.692
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                0.692
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
| Net cash provided by (used in) operating activities | 
                                                1,349,416,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                1,915,190,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                1,259,138,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Net cash provided by (used in) investing activities | 
                                                -2,404,832,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -2,897,286,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -325,400,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Net cash provided by (used in) financing activities | 
                                                1,870,581,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -1,314,445,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -974,563,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Cash and cash equivalents | — | 
                                                5,031,858,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                4,022,190,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                6,291,825,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             |