Balance Sheet
| Concept | As at 2023-12-31 | As at 2023-03-31 | 
|---|---|---|
| Balance sheet | ||
| Balance sheet | ||
| Assets | ||
| Current assets | ||
| Cash and deposits | 
                                                19,081,434,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                18,370,835,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Inventories | 
                                                45,890,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                40,790,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Allowance for doubtful accounts | 
                                                -1,919,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -79,903,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Other | 
                                                1,113,986,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                684,493,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Current assets | 
                                                26,782,987,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                25,458,464,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Non-current assets | ||
| Property, plant and equipment | ||
| Land | 
                                                6,787,415,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                6,787,415,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Property, plant and equipment | 
                                                9,177,800,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                8,692,920,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Other, net | 
                                                1,047,945,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                493,628,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Other | — | — | 
| Own-used assets | ||
| Intangible assets | 
                                                147,158,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                73,859,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Other | 
                                                147,158,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                73,859,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Intangible assets | ||
| Other intangible assets | ||
| Investments and other assets | ||
| Investment securities | 
                                                120,998,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                109,039,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Investments and other assets | 
                                                1,875,589,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,973,521,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Deferred tax assets | 
                                                674,654,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                755,777,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Other | 
                                                306,605,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                300,554,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Non-current assets | 
                                                11,200,548,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                10,740,301,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Other assets | — | — | 
| Other assets | ||
| Assets | 
                                                37,983,535,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                36,198,765,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Liabilities | ||
| Current liabilities | ||
| Accounts payable - trade | 
                                                2,299,590,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                2,318,746,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Accounts payable - other | 
                                                771,256,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                382,062,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Income taxes payable | 
                                                560,390,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                736,039,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Other | 
                                                1,304,620,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,266,825,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Current liabilities | 
                                                6,362,097,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                6,287,860,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Accrued consumption taxes | 
                                                895,761,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                881,052,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Provision for bonuses | 
                                                530,479,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                703,134,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Provisions | ||
| Non-current liabilities | ||
| Non-current liabilities | 
                                                1,493,538,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,446,941,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Other | 
                                                250,267,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                250,093,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Asset retirement obligations | 
                                                265,647,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                265,167,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Provision for retirement benefits for directors (and other officers) | 
                                                526,690,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                511,133,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Liabilities | 
                                                7,855,636,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                7,734,802,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Other liabilities | — | — | 
| Other liabilities | — | — | 
| Liabilities and net assets | ||
| Shareholders' equity | 
                                                28,907,735,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                27,482,924,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Share capital | 
                                                1,000,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,000,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Capital surplus | 
                                                710,328,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                710,799,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Retained earnings | 
                                                28,474,596,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                27,049,315,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Treasury shares | 
                                                -1,277,189,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -1,277,189,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Valuation and translation adjustments | 
                                                205,538,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                124,472,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Valuation difference on available-for-sale securities | 
                                                36,279,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                27,977,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Net assets | 
                                                30,127,899,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                28,463,963,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Liabilities and net assets | 
                                                37,983,535,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                36,198,765,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Net assets | ||
| Shareholders' equity | ||
| Capital surplus | ||
| Retained earnings | ||
| Valuation and translation adjustments |