Consolidated Balance Sheet
| Concept | As at 2023-12-31 | As at 2023-06-30 | 
|---|---|---|
| Consolidated balance sheet | ||
| Balance sheet | ||
| Assets | ||
| Non-current assets | ||
| Property, plant and equipment | ||
| Buildings and structures | — | — | 
| Buildings and structures, net | 
                                                1,156,738,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,192,018,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Own-used assets | ||
| Machinery, equipment and vehicles | — | — | 
| Machinery, equipment and vehicles, net | 
                                                333,962,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                319,312,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Land | 
                                                1,202,086,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,202,086,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Leased assets | — | — | 
| Leased assets, net | 
                                                36,687,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                24,222,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Construction in progress | 
                                                6,647,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Other | — | — | 
| Other, net | 
                                                58,648,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                66,397,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Property, plant and equipment | 
                                                2,794,770,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                2,804,037,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Intangible assets | ||
| Goodwill | 
                                                169,325,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                182,350,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Other | 
                                                5,943,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                5,943,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Other intangible assets | ||
| Intangible assets | 
                                                220,897,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                242,345,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Software | 
                                                45,628,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                54,050,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Investments and other assets | ||
| Investment securities | 
                                                73,920,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                73,301,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Long-term loans receivable | 
                                                34,457,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                34,457,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Deferred tax assets | 
                                                235,814,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                250,998,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Other | 
                                                187,258,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                185,511,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Allowance for doubtful accounts | 
                                                -39,748,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -39,756,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Investments and other assets | 
                                                584,125,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                599,783,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Guarantee deposits | 
                                                77,209,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                79,792,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Non-current assets | 
                                                3,599,793,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                3,646,165,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Current assets | ||
| Cash and deposits | 
                                                647,018,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                651,230,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Work in process | 
                                                955,314,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                379,337,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Prepaid expenses | 
                                                49,848,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                62,040,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Supplies | 
                                                8,642,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                6,470,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Other | 
                                                28,828,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                13,347,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Allowance for doubtful accounts | 
                                                -21,492,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -19,372,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Current assets | 
                                                2,539,685,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,597,303,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Assets | 
                                                6,139,478,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                5,243,468,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Liabilities | ||
| Non-current liabilities | ||
| Long-term borrowings | 
                                                736,078,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                803,175,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Bonds payable | 
                                                90,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                108,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Lease liabilities | 
                                                21,456,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                12,903,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Retirement benefit liability | 
                                                598,980,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                602,081,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Provision for retirement benefits for directors (and other officers) | 
                                                4,082,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                4,082,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Non-current liabilities | 
                                                1,479,490,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,560,650,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Asset retirement obligations | 
                                                14,432,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                14,378,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Other | 
                                                14,460,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                16,029,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Current liabilities | ||
| Short-term borrowings | 
                                                1,450,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                630,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Notes and accounts payable - trade | 
                                                202,718,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                66,389,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Accounts payable - other | 
                                                197,484,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                120,720,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Income taxes payable | 
                                                17,766,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                49,276,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Lease liabilities | 
                                                20,609,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                15,933,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Current portion of long-term borrowings | 
                                                134,143,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                132,709,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Current portion of bonds payable | 
                                                36,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                36,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Accrued expenses | 
                                                98,192,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                219,202,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Provisions | ||
| Provision for bonuses | 
                                                956,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                5,683,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Other | 
                                                63,752,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                71,035,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Current liabilities | 
                                                2,472,744,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,448,546,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Liabilities | 
                                                3,952,234,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                3,009,196,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Liabilities and net assets | ||
| Shareholders' equity | 
                                                2,080,275,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                2,130,287,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Share capital | 
                                                870,441,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                870,441,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Capital surplus | 
                                                819,356,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                819,356,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Retained earnings | 
                                                390,635,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                440,648,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Treasury shares | 
                                                -159,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -159,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Valuation and translation adjustments | 
                                                3,103,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                3,090,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Valuation difference on available-for-sale securities | 
                                                1,253,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                931,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Foreign currency translation adjustment | 
                                                1,850,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                2,158,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Share acquisition rights | 
                                                28,140,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                28,140,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Non-controlling interests | 
                                                75,725,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                72,754,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Net assets | 
                                                2,187,243,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                2,234,272,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Liabilities and net assets | 
                                                6,139,478,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                5,243,468,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Net assets | ||
| Shareholders' equity | ||
| Valuation and translation adjustments |