Semi-Annual Balance Sheet
| Concept | As at 2024-06-30 | As at 2023-12-31 | 
|---|---|---|
| Semi-annual balance sheet | ||
| Balance sheet | ||
| Assets | ||
| Current assets | ||
| Cash and deposits | 
                                                841,362,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                878,861,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Inventories | 
                                                4,677,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                3,957,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Other | 
                                                69,573,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                68,850,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Allowance for doubtful accounts | 
                                                -2,203,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -2,548,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Current assets | 
                                                1,074,766,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,114,958,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Non-current assets | ||
| Property, plant and equipment | ||
| Property, plant and equipment | 
                                                158,890,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                162,030,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Other | — | — | 
| Other, net | 
                                                43,438,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                43,082,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Intangible assets | ||
| Intangible assets | 
                                                396,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                448,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Investments and other assets | ||
| Investments and other assets | 
                                                86,711,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                78,643,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Allowance for doubtful accounts | 
                                                -3,178,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -2,828,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Non-current assets | 
                                                245,998,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                241,122,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Assets | 
                                                1,320,764,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,356,081,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Liabilities | ||
| Current liabilities | ||
| Short-term borrowings | 
                                                450,196,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                450,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Income taxes payable | 
                                                4,445,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                20,151,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Other | 
                                                59,999,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                87,568,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Current liabilities | 
                                                692,098,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                715,820,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Accounts payable - other | 
                                                74,154,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                63,969,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Non-current liabilities | ||
| Non-current liabilities | 
                                                210,958,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                241,856,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Long-term borrowings | 
                                                117,976,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                145,480,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Asset retirement obligations | 
                                                39,903,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                40,186,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Other | 
                                                6,458,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                11,689,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Liabilities | 
                                                903,057,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                957,677,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Other liabilities | — | — | 
| Provision for bonuses | 
                                                11,597,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                9,107,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Deferred tax liabilities | 
                                                31,774,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                31,154,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Other liabilities | — | — | 
| Net assets | ||
| Shareholders' equity | ||
| Share capital | 
                                                10,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                514,068,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Capital surplus | ||
| Capital surplus | 
                                                267,022,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                399,886,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Retained earnings | ||
| Retained earnings | 
                                                215,610,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -445,445,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Treasury shares | 
                                                -71,335,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -71,335,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Shareholders' equity | 
                                                421,297,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                397,172,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Valuation and translation adjustments | ||
| Valuation difference on available-for-sale securities | 
                                                -621,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                30,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Valuation and translation adjustments | 
                                                -5,338,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -1,800,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Net assets | 
                                                417,707,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                398,404,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Liabilities and net assets | 
                                                1,320,764,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,356,081,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             |