Consolidated Balance Sheet
| Concept | As at 2023-09-30 | As at 2023-03-31 | 
|---|---|---|
| Consolidated balance sheet | ||
| Balance sheet | ||
| Assets | ||
| Current assets | ||
| Cash and deposits | 
                                                16,936,678,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                15,358,306,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Other | 
                                                2,448,139,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                2,699,044,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Allowance for doubtful accounts | 
                                                -13,422,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -13,363,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Current assets | 
                                                27,669,217,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                27,702,869,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Non-current assets | ||
| Property, plant and equipment | ||
| Buildings and structures | — | — | 
| Buildings and structures, net | 
                                                5,978,431,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                5,823,184,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Own-used assets | ||
| Machinery, equipment and vehicles | — | — | 
| Machinery, equipment and vehicles, net | 
                                                1,084,634,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                827,153,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Land | 
                                                14,066,701,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                12,849,497,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Leased assets | — | — | 
| Leased assets, net | 
                                                160,866,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                159,337,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Construction in progress | 
                                                1,034,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,034,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Other | — | — | 
| Other, net | 
                                                825,120,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                820,771,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Property, plant and equipment | 
                                                22,116,788,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                20,480,977,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Intangible assets | ||
| Other intangible assets | ||
| Other | 
                                                70,763,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                83,237,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Intangible assets | 
                                                70,763,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                83,237,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Investments and other assets | ||
| Investment securities | 
                                                5,100,690,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                4,510,176,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Long-term loans receivable | 
                                                333,518,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                340,238,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Investments in capital | 
                                                1,760,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,760,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Deferred tax assets | 
                                                858,770,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,038,153,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Other | 
                                                617,906,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                618,565,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Allowance for doubtful accounts | 
                                                -28,968,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -29,523,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Investments and other assets | 
                                                6,883,677,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                6,479,370,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Non-current assets | 
                                                29,071,229,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                27,043,585,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Assets | 
                                                56,740,446,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                54,746,455,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Liabilities and net assets | ||
| Non-current liabilities | 
                                                5,026,398,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                4,761,135,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Long-term borrowings | 
                                                151,272,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                160,833,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Lease liabilities | 
                                                616,296,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                634,124,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Retirement benefit liability | 
                                                3,720,202,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                3,630,356,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Asset retirement obligations | 
                                                195,410,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                193,158,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Current liabilities | 
                                                7,956,890,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                8,541,478,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Short-term borrowings | 
                                                466,396,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                66,396,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Liabilities | 
                                                12,983,289,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                13,302,614,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Shareholders' equity | 
                                                39,288,660,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                38,345,455,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Share capital | 
                                                2,046,941,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                2,046,941,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Capital surplus | 
                                                1,464,060,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,464,060,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Retained earnings | 
                                                36,996,572,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                36,053,092,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Treasury shares | 
                                                -1,218,913,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -1,218,638,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Valuation and translation adjustments | 
                                                2,893,271,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,635,851,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Valuation difference on available-for-sale securities | 
                                                1,801,285,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,422,543,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Foreign currency translation adjustment | 
                                                1,050,855,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                158,817,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Non-controlling interests | 
                                                1,575,224,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,462,533,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Net assets | 
                                                43,757,157,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                41,443,840,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Liabilities and net assets | 
                                                56,740,446,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                54,746,455,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Liabilities | ||
| Current liabilities | ||
| Income taxes payable | 
                                                768,568,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,254,119,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Current portion of long-term borrowings | 
                                                18,314,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                20,811,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Lease liabilities | 
                                                258,691,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                230,095,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Provisions | ||
| Provision for bonuses | 
                                                1,003,549,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                958,457,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Other | 
                                                1,602,908,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,636,878,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Non-current liabilities | ||
| Other | 
                                                343,216,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                142,662,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Net assets | ||
| Shareholders' equity | ||
| Valuation and translation adjustments | ||
| Remeasurements of defined benefit plans | 
                                                41,131,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                54,490,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             |