Quarterly Consolidated Balance Sheet
| Concept | As at 2024-09-30 | As at 2024-03-31 | 
|---|---|---|
| Quarterly consolidated balance sheet | ||
| Balance sheet | ||
| Assets | ||
| Current assets | ||
| Cash and deposits | 
                                                2,468,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                4,539,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Raw materials and supplies | 
                                                98,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                88,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Other | 
                                                600,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                587,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Allowance for doubtful accounts | 
                                                -20,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -24,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Current assets | 
                                                4,209,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                6,318,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Non-current assets | ||
| Property, plant and equipment | 
                                                2,518,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,681,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Property, plant and equipment | ||
| Buildings and structures | — | — | 
| Buildings and structures, net | 
                                                1,250,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,175,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Other | — | — | 
| Other, net | 
                                                136,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                123,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Intangible assets | ||
| Intangible assets | 
                                                124,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                117,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Investments and other assets | 
                                                2,816,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                2,731,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Investments and other assets | ||
| Deferred tax assets | 
                                                1,009,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                971,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Other | 
                                                85,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                68,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Allowance for doubtful accounts | 
                                                -15,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -15,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Non-current assets | 
                                                5,459,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                4,531,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Assets | 
                                                9,668,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                10,849,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Liabilities | ||
| Current liabilities | ||
| Income taxes payable | 
                                                154,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                213,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Asset retirement obligations | 
                                                22,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                32,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Other | 
                                                507,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                734,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Current liabilities | 
                                                3,686,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                3,919,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Non-current liabilities | ||
| Long-term borrowings | 
                                                400,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                600,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Asset retirement obligations | 
                                                806,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                803,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Other | 
                                                474,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                496,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Non-current liabilities | 
                                                1,761,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,981,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Liabilities | 
                                                5,448,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                5,900,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Net assets | ||
| Shareholders' equity | ||
| Share capital | 
                                                2,044,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                3,029,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Capital surplus | 
                                                2,307,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                2,805,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Retained earnings | 
                                                -581,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -1,220,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Treasury shares | 
                                                0
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                0
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Shareholders' equity | 
                                                3,769,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                4,615,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Valuation and translation adjustments | ||
| Foreign currency translation adjustment | 
                                                256,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                167,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Valuation and translation adjustments | 
                                                256,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                167,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Non-controlling interests | 
                                                193,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                166,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Net assets | 
                                                4,220,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                4,949,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Liabilities and net assets | 
                                                9,668,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                10,849,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             |