Notes - Segment Information
| Concept | 2023-01-01 to 2023-12-31 | 2023-01-01 to 2023-12-31 | As at 2023-12-31 | 2023-01-01 to 2023-12-31 | 2023-01-01 to 2023-12-31 | As at 2023-12-31 | 2023-01-01 to 2023-12-31 | As at 2023-12-31 | As at 2023-12-31 | As at 2023-12-31 | As at 2022-12-31 | As at 2022-12-31 | 2022-01-01 to 2022-12-31 | 2022-01-01 to 2022-12-31 | 2022-01-01 to 2022-12-31 | 2022-01-01 to 2022-12-31 | As at 2022-12-31 | 2022-01-01 to 2022-12-31 | As at 2022-12-31 | As at 2022-12-31 | 
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Notes - Segment information | ||||||||||||||||||||
| Segment information | ||||||||||||||||||||
| Segment profit (loss) | 
                                                220,434,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                220,434,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -59,191,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                279,625,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                2,110,076,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                2,110,076,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -17,982,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                2,128,058,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Share of profit (loss) of investments accounted for using equity method | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | 
                                                3,788,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | 
| Profit (loss) before tax | — | 
                                                287,471,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | 
                                                1,875,084,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | 
| Assets | — | — | 
                                                8,490,467,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                8,278,903,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                211,572,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -9,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                8,490,476,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                8,471,270,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                8,471,270,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                8,340,173,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                131,097,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Depreciation and amortization | 
                                                457,488,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                457,488,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                457,488,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                428,308,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                428,308,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                428,308,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — |