Semi-Annual Consolidated Balance Sheet
| Concept | As at 2023-12-31 | As at 2023-03-31 | 
|---|---|---|
| Semi-annual consolidated balance sheet | ||
| Balance sheet | ||
| Assets | ||
| Current assets | ||
| Cash and deposits | 
                                                627,554,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                640,084,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Other | 
                                                74,642,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                100,165,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Allowance for doubtful accounts | 
                                                -1,290,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -174,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Current assets | 
                                                2,600,552,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                3,025,273,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Non-current assets | ||
| Property, plant and equipment | 
                                                2,607,911,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                2,617,722,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Property, plant and equipment | ||
| Land | 
                                                1,680,159,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,680,159,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Construction in progress | 
                                                71,441,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                64,016,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Other | — | — | 
| Other, net | 
                                                193,391,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                192,314,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Intangible assets | ||
| Intangible assets | 
                                                70,857,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                81,263,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Investments and other assets | 
                                                336,747,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                337,976,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Investments and other assets | ||
| Investment securities | 
                                                24,992,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                22,586,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Other | 
                                                314,955,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                318,873,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Allowance for doubtful accounts | 
                                                -3,200,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -3,482,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Non-current assets | 
                                                3,015,516,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                3,036,962,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Assets | 
                                                5,616,068,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                6,062,236,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Liabilities | ||
| Current liabilities | ||
| Notes and accounts payable - trade | 
                                                244,477,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                950,402,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Short-term borrowings | 
                                                1,300,573,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,166,294,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Income taxes payable | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                65,507,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Other | 
                                                251,852,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                452,700,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Current liabilities | 
                                                1,823,291,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                2,714,783,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Non-current liabilities | ||
| Long-term borrowings | 
                                                575,822,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                177,598,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Asset retirement obligations | 
                                                1,747,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,728,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Non-current liabilities | 
                                                757,410,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                334,948,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Liabilities | 
                                                2,580,702,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                3,049,732,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Provision for retirement benefits for directors (and other officers) | 
                                                4,350,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                4,350,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Provision for bonuses | 
                                                26,389,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                79,879,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Net assets | ||
| Shareholders' equity | ||
| Share capital | 
                                                664,740,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                664,740,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Capital surplus | 
                                                268,757,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                267,245,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Retained earnings | 
                                                2,178,532,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                2,163,443,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Treasury shares | 
                                                -89,945,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -94,534,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Shareholders' equity | 
                                                3,022,085,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                3,000,895,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Valuation and translation adjustments | ||
| Valuation difference on available-for-sale securities | 
                                                13,281,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                11,609,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Valuation and translation adjustments | 
                                                13,281,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                11,609,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Net assets | 
                                                3,035,366,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                3,012,504,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Liabilities and net assets | 
                                                5,616,068,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                6,062,236,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             |