Key Financial Data Of Group
| Concept | 2024-01-01 to 2024-03-31 | As at 2024-03-31 | 2023-01-01 to 2023-12-31 | As at 2023-12-31 | 2023-01-01 to 2023-03-31 | As at 2023-03-31 | 
|---|---|---|---|---|---|---|
| Key financial data of group | ||||||
| Business results of group | ||||||
| Revenue | 
                                                1,171,986,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                4,739,514,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                1,134,161,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Profit (loss) before tax | 
                                                137,567,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                287,471,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                76,087,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Profit (loss), attributable to owners of parent | 
                                                87,226,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                226,603,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                51,429,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Comprehensive income, attributable to owners of parent | 
                                                275,408,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                167,452,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -2,152,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Equity attributable to owners of parent | — | 
                                                6,412,802,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                6,137,394,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                5,949,989,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Total assets | — | 
                                                8,721,521,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                8,490,467,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                8,450,616,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Basic earnings (loss) per share | 
                                                5.56
                                                
                                             | — | 
                                                14.47
                                                
                                             | — | 
                                                3.30
                                                
                                             | — | 
| Diluted earnings (loss) per share |  | — | 
                                                14.46
                                                
                                             | — | 
                                                3.29
                                                
                                             | — | 
| Ratio of owners' equity to gross assets | — | 
                                                0.735
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                0.723
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                0.704
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
| Cash flows from (used in) operating activities | 
                                                230,655,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                698,108,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                2,075,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Cash flows from (used in) investing activities | 
                                                -56,568,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -716,182,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -363,888,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Cash flows from (used in) financing activities | 
                                                -44,694,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -154,515,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -39,479,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Cash and cash equivalents | — | 
                                                3,700,715,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                3,495,505,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                3,201,851,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             |