Quarterly Consolidated Balance Sheet
| Concept | As at 2024-03-31 | As at 2023-12-31 | 
|---|---|---|
| Quarterly consolidated balance sheet | ||
| Balance sheet | ||
| Assets | ||
| Current assets | ||
| Cash and deposits | 
                                                3,182,991,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                3,403,321,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Inventories | 
                                                22,064,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                43,375,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Other | 
                                                118,663,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                139,707,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Current assets | 
                                                3,492,204,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                3,718,927,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Non-current assets | ||
| Property, plant and equipment | 
                                                95,747,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                98,736,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Property, plant and equipment | ||
| Intangible assets | ||
| Other | 
                                                103,393,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                93,678,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Intangible assets | 
                                                300,864,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                274,627,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Investments and other assets | 
                                                207,007,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                213,171,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Investments and other assets | ||
| Investment securities | 
                                                44,328,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                38,736,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Deferred tax assets | 
                                                28,039,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                38,918,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Other | 
                                                16,043,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                16,043,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Non-current assets | 
                                                603,620,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                586,534,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Assets | 
                                                4,095,824,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                4,305,462,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Liabilities | ||
| Current liabilities | ||
| Income taxes payable | 
                                                7,809,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                12,434,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Other | 
                                                29,848,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                21,020,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Current liabilities | 
                                                1,136,288,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,322,045,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Non-current liabilities | ||
| Retirement benefit liability | 
                                                1,603,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,591,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Asset retirement obligations | 
                                                38,682,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                38,460,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Other | 
                                                1,340,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,340,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Non-current liabilities | 
                                                41,625,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                41,392,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Liabilities | 
                                                1,177,914,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,363,438,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Net assets | ||
| Shareholders' equity | ||
| Share capital | 
                                                589,813,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                589,813,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Capital surplus | 
                                                578,170,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                578,170,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Retained earnings | 
                                                1,755,568,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,783,141,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Treasury shares | 
                                                -39,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -39,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Shareholders' equity | 
                                                2,923,512,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                2,951,085,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Valuation and translation adjustments | ||
| Valuation difference on available-for-sale securities | 
                                                27,979,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                24,099,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Foreign currency translation adjustment | 
                                                -33,582,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -33,160,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Valuation and translation adjustments | 
                                                -5,602,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -9,060,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Net assets | 
                                                2,917,909,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                2,942,024,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Liabilities and net assets | 
                                                4,095,824,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                4,305,462,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             |