Semi-Annual Consolidated Balance Sheet
| Concept | As at 2024-09-30 | As at 2024-03-31 | 
|---|---|---|
| Semi-annual consolidated balance sheet | ||
| Balance sheet | ||
| Assets | ||
| Current assets | ||
| Cash and deposits | 
                                                2,124,649,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                2,528,061,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Other | 
                                                854,549,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                153,494,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Current assets | 
                                                3,656,015,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                3,260,525,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Non-current assets | ||
| Property, plant and equipment | 
                                                6,411,441,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                6,809,009,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Property, plant and equipment | ||
| Land | 
                                                167,363,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                167,363,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Construction in progress | 
                                                1,051,300,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,053,896,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Other | — | — | 
| Other, net | 
                                                16,863,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                18,379,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Intangible assets | ||
| Intangible assets | 
                                                8,927,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                9,835,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Investments and other assets | 
                                                1,701,621,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,738,745,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Investments and other assets | ||
| Investment securities | 
                                                1,088,799,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,132,487,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Deferred tax assets | 
                                                445,679,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                432,377,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Other | 
                                                74,323,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                80,744,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Non-current assets | 
                                                8,121,990,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                8,557,590,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Assets | 
                                                11,778,005,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                11,818,116,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Retirement benefit asset | 
                                                92,818,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                93,135,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Liabilities | ||
| Current liabilities | ||
| Income taxes payable | 
                                                70,954,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                130,740,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Other | 
                                                73,579,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                148,934,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Current liabilities | 
                                                1,179,755,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,014,952,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Non-current liabilities | ||
| Long-term borrowings | 
                                                2,108,824,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                2,297,661,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Retirement benefit liability | 
                                                65,253,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                61,848,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Asset retirement obligations | 
                                                14,641,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                14,519,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Other | 
                                                105,111,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                106,375,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Non-current liabilities | 
                                                3,039,582,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                3,429,300,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Liabilities | 
                                                4,219,337,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                4,444,252,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Provision for bonuses | 
                                                32,282,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                32,535,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Deferred tax liabilities | 
                                                671,310,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                665,021,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Net assets | ||
| Share capital | 
                                                702,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                702,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Shareholders' equity | ||
| Capital surplus | 
                                                373,529,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                373,529,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Retained earnings | 
                                                5,956,905,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                5,743,946,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Treasury shares | 
                                                -2,244,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -2,117,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Shareholders' equity | 
                                                7,030,189,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                6,817,358,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Valuation and translation adjustments | ||
| Valuation difference on available-for-sale securities | 
                                                486,170,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                511,932,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Valuation and translation adjustments | 
                                                486,170,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                511,932,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Non-controlling interests | 
                                                42,307,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                44,572,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Net assets | 
                                                7,558,667,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                7,373,863,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Liabilities and net assets | 
                                                11,778,005,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                11,818,116,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             |