Semi-Annual Consolidated Balance Sheet
| Concept | As at 2024-03-31 | As at 2023-12-31 | 
|---|---|---|
| Semi-annual consolidated balance sheet | ||
| Balance sheet | ||
| Assets | ||
| Current assets | ||
| Cash and deposits | 
                                                2,286,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                2,121,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Other | 
                                                571,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                584,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Allowance for doubtful accounts | 
                                                -30,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -30,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Current assets | 
                                                3,580,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                3,456,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Non-current assets | ||
| Property, plant and equipment | 
                                                734,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                762,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Property, plant and equipment | ||
| Other | 
                                                133,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                142,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Intangible assets | ||
| Intangible assets | 
                                                51,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                55,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Investments and other assets | 
                                                1,377,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,365,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Investments and other assets | ||
| Other | 
                                                261,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                237,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Allowance for doubtful accounts | 
                                                -11,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -3,475,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Non-current assets | 
                                                2,164,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                2,184,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Assets | 
                                                5,744,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                5,641,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Liabilities | ||
| Current liabilities | ||
| Short-term borrowings | 
                                                47,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                31,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Income taxes payable | 
                                                26,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                68,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Asset retirement obligations | 
                                                34,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                50,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Other | 
                                                431,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                445,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Current liabilities | 
                                                2,078,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                2,285,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Non-current liabilities | ||
| Long-term borrowings | 
                                                28,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                31,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Asset retirement obligations | 
                                                402,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                397,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Other | 
                                                374,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                380,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Non-current liabilities | 
                                                810,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                814,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Liabilities | 
                                                2,888,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                3,100,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Provision for bonuses | 
                                                12,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Net assets | ||
| Shareholders' equity | ||
| Share capital | 
                                                194,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                10,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Capital surplus | 
                                                3,416,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                3,231,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Retained earnings | 
                                                -761,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -710,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Treasury shares | 
                                                0
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                0
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Shareholders' equity | 
                                                2,849,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                2,530,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Valuation and translation adjustments | ||
| Valuation difference on available-for-sale securities | 
                                                -1,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -2,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Deferred gains or losses on hedges | 
                                                0
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -1,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Valuation and translation adjustments | 
                                                -2,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -3,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Share acquisition rights | 
                                                8,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                14,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Net assets | 
                                                2,855,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                2,540,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Liabilities and net assets | 
                                                5,744,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                5,641,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             |