Balance Sheet
| Concept | As at 2023-09-30 | As at 2023-03-31 | 
|---|---|---|
| Balance sheet | ||
| Balance sheet | ||
| Assets | ||
| Current assets | 
                                                17,530,311,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                20,901,086,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Cash and deposits | 
                                                7,206,296,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                8,352,014,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Notes receivable - trade | 
                                                105,389,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                174,665,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Accounts receivable - trade | 
                                                2,154,417,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                2,876,336,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Securities | 
                                                1,500,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Merchandise | 
                                                102,644,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                103,269,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Other | 
                                                210,072,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                496,182,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Allowance for doubtful accounts | 
                                                -11,216,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -10,112,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Non-current assets | ||
| Property, plant and equipment | ||
| Land | 
                                                2,132,462,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                2,132,462,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Property, plant and equipment | 
                                                3,386,703,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                3,375,833,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Other, net | 
                                                289,152,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                288,332,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Other | 
                                                1,159,598,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,137,246,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Accumulated depreciation | 
                                                -870,446,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -848,913,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Own-used assets | ||
| Intangible assets | 
                                                93,861,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                85,705,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Intangible assets | ||
| Investments and other assets | ||
| Investment securities | 
                                                4,871,315,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                4,206,839,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Investments and other assets | 
                                                5,319,132,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                4,752,562,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Other | 
                                                734,991,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                806,837,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Allowance for doubtful accounts | 
                                                -287,174,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -261,114,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Non-current assets | 
                                                8,799,697,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                8,214,101,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Other assets | — | — | 
| Current assets | ||
| Contract assets | 
                                                2,032,689,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                3,586,047,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Accounts receivable from completed construction contracts | 
                                                848,716,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                2,508,908,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Costs on construction contracts in progress | 
                                                380,675,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                341,379,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Raw materials and supplies | 
                                                76,320,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                34,153,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Work in process | 
                                                958,015,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                696,254,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Other assets | ||
| Assets | 
                                                26,330,008,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                29,115,187,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Liabilities and net assets | ||
| Non-current liabilities | 
                                                1,578,310,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,546,770,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Other | 
                                                138,645,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                114,845,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Current liabilities | 
                                                7,899,357,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                11,124,658,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Notes payable - trade | 
                                                220,588,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                2,118,305,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Short-term borrowings | 
                                                955,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                855,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Accounts payable - trade | 
                                                1,243,631,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                2,028,038,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Income taxes payable | 
                                                148,069,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                489,492,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Other | 
                                                623,979,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                716,153,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Liabilities | 
                                                9,477,668,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                12,671,428,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Shareholders' equity | 
                                                16,258,161,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                15,909,701,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Share capital | 
                                                1,029,213,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,029,213,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Capital surplus | 
                                                832,450,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                826,086,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Retained earnings | 
                                                15,608,737,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                15,272,794,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Treasury shares | 
                                                -1,212,239,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -1,218,393,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Valuation and translation adjustments | 
                                                594,178,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                534,057,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Valuation difference on available-for-sale securities | 
                                                546,287,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                482,739,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Net assets | 
                                                16,852,340,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                16,443,759,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Liabilities and net assets | 
                                                26,330,008,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                29,115,187,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Liabilities | ||
| Current liabilities | ||
| Accounts payable for construction contracts | 
                                                929,639,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                2,372,906,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Contract liabilities | 
                                                1,823,659,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,274,675,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Provision for bonuses | 
                                                175,293,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                352,436,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Provisions | ||
| Provision for bonuses for directors (and other officers) | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                52,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Non-current liabilities | ||
| Provision for retirement benefits for directors (and other officers) | 
                                                108,235,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                109,005,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Other liabilities | — | — | 
| Other liabilities | — | — | 
| Net assets | ||
| Valuation and translation adjustments | ||
| Shareholders' equity | ||
| Capital surplus | ||
| Retained earnings |