Consolidated Balance Sheet
| Concept | As at 2023-12-31 | As at 2023-03-31 | 
|---|---|---|
| Consolidated balance sheet | ||
| Balance sheet | ||
| Assets | ||
| Current assets | ||
| Cash and deposits | 
                                                4,734,621,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                5,260,023,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Securities | 
                                                50,051,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                47,395,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Merchandise and finished goods | 
                                                99,608,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                58,811,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Work in process | 
                                                34,113,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                23,338,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Raw materials and supplies | 
                                                18,558,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                36,824,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Other | 
                                                526,635,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                345,967,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Allowance for doubtful accounts | 
                                                -6,744,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -6,311,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Current assets | 
                                                6,977,324,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                7,276,997,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Non-current assets | ||
| Property, plant and equipment | ||
| Buildings and structures | — | — | 
| Buildings and structures, net | 
                                                2,047,173,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                2,140,099,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Own-used assets | ||
| Machinery, equipment and vehicles | — | — | 
| Machinery, equipment and vehicles, net | 
                                                55,405,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                74,234,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Land | 
                                                2,751,035,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                2,748,872,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Leased assets | — | — | 
| Leased assets, net | 
                                                159,209,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                103,779,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Other | — | — | 
| Other, net | 
                                                100,523,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                49,405,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Property, plant and equipment | 
                                                5,113,346,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                5,116,390,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Intangible assets | 
                                                278,593,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                253,738,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Goodwill | 
                                                251,317,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                231,216,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Other | 
                                                27,275,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                22,522,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Intangible assets | ||
| Other intangible assets | ||
| Investments and other assets | ||
| Investment securities | 
                                                939,380,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                701,829,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Other | 
                                                1,105,513,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,078,912,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Allowance for doubtful accounts | 
                                                -1,380,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -1,380,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Investments and other assets | 
                                                2,043,513,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,779,361,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Non-current assets | 
                                                7,435,454,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                7,149,491,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Assets | 
                                                14,412,778,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                14,426,489,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Liabilities | ||
| Current liabilities | ||
| Short-term borrowings | 
                                                50,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                50,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Income taxes payable | 
                                                30,060,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                141,286,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Lease liabilities | 
                                                49,914,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                31,895,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Current portion of long-term borrowings | 
                                                225,024,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                207,884,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Provisions | ||
| Provision for bonuses | 
                                                83,750,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                148,082,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Other | 
                                                407,809,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                380,824,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Current liabilities | 
                                                2,307,457,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                2,369,016,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Advances received | 
                                                402,495,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                406,482,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Non-current liabilities | ||
| Long-term borrowings | 
                                                3,023,666,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                3,155,025,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Lease liabilities | 
                                                127,916,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                83,803,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Retirement benefit liability | 
                                                1,198,773,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,181,698,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Provision for retirement benefits for directors (and other officers) | 
                                                109,013,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                101,918,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Other | 
                                                23,728,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                26,471,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Non-current liabilities | 
                                                4,483,099,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                4,548,916,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Liabilities | 
                                                6,790,556,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                6,917,932,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Liabilities and net assets | ||
| Shareholders' equity | 
                                                7,581,919,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                7,496,871,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Share capital | 
                                                750,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                750,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Capital surplus | 
                                                1,047,847,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,047,847,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Retained earnings | 
                                                6,301,021,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                6,215,974,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Treasury shares | 
                                                -516,950,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -516,950,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Valuation and translation adjustments | 
                                                40,302,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                11,684,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Valuation difference on available-for-sale securities | 
                                                42,495,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                14,384,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Non-controlling interests | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Net assets | 
                                                7,622,221,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                7,508,556,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Liabilities and net assets | 
                                                14,412,778,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                14,426,489,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Net assets | ||
| Shareholders' equity | ||
| Valuation and translation adjustments | ||
| Remeasurements of defined benefit plans | 
                                                -2,193,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -2,699,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             |