Quarterly Balance Sheet
| Concept | As at 2024-06-30 | As at 2023-12-31 | 
|---|---|---|
| Quarterly balance sheet | ||
| Balance sheet | ||
| Assets | ||
| Current assets | ||
| Cash and deposits | 
                                                3,343,452,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                3,403,321,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Inventories | 
                                                19,271,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                43,375,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Other | 
                                                140,005,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                139,707,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Current assets | 
                                                3,694,385,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                3,718,927,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Non-current assets | ||
| Property, plant and equipment | 
                                                93,415,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                98,736,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Property, plant and equipment | ||
| Tools, furniture and fixtures | — | — | 
| Tools, furniture and fixtures, net | 
                                                11,953,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                12,269,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Intangible assets | 
                                                335,382,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                274,627,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Intangible assets | ||
| Software | 
                                                186,200,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                180,948,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Other | 
                                                149,182,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                93,678,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Investments and other assets | 
                                                222,833,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                213,171,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Investments and other assets | ||
| Investment securities | 
                                                45,288,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                38,736,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Deferred tax assets | 
                                                31,695,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                38,918,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Other | 
                                                16,043,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                16,043,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Non-current assets | 
                                                651,630,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                586,534,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Assets | 
                                                4,346,016,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                4,305,462,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Liabilities | ||
| Current liabilities | ||
| Income taxes payable | 
                                                28,640,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                12,434,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Other | 
                                                19,672,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                21,124,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Current liabilities | 
                                                1,301,757,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,322,045,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Non-current liabilities | ||
| Asset retirement obligations | 
                                                39,048,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                38,460,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Other | 
                                                1,340,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,340,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Non-current liabilities | 
                                                42,068,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                41,392,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Liabilities | 
                                                1,343,826,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,363,438,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Net assets | ||
| Shareholders' equity | ||
| Share capital | 
                                                605,305,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                589,813,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Capital surplus | 
                                                593,662,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                578,170,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Retained earnings | 
                                                1,795,720,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,783,141,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Treasury shares | 
                                                -39,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -39,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Shareholders' equity | 
                                                2,994,648,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                2,951,085,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Valuation and translation adjustments | ||
| Valuation difference on available-for-sale securities | 
                                                28,645,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                24,099,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Valuation and translation adjustments | 
                                                7,542,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -9,060,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Net assets | 
                                                3,002,190,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                2,942,024,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Liabilities and net assets | 
                                                4,346,016,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                4,305,462,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             |