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 | 
                                                5,260,440,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                2,597,664,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Accounts receivable - trade | 
                                                1,376,456,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,310,690,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Merchandise and finished goods | 
                                                874,597,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                622,297,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Work in process | 
                                                2,712,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                5,330,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Prepaid expenses | 
                                                337,617,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                456,027,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Raw materials and supplies | 
                                                713,562,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,096,972,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Other | 
                                                61,641,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                115,636,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Allowance for doubtful accounts | 
                                                -3,730,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -4,917,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Current assets | 
                                                8,626,738,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                6,199,701,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Non-current assets | 
                                                13,951,359,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                13,851,954,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Investments and other assets | 
                                                3,418,741,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                3,529,126,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Investment securities | 
                                                168,734,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                150,809,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Long-term loans receivable | 
                                                3,802,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,885,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Long-term prepaid expenses | 
                                                71,863,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                85,575,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Deferred tax assets | 
                                                127,877,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                165,834,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Other | 
                                                27,556,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                27,998,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Allowance for doubtful accounts | 
                                                -24,416,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -26,721,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Non-current assets | ||
| Property, plant and equipment | ||
| Buildings and structures | — | — | 
| Buildings and structures, net | 
                                                3,160,719,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                3,153,797,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Own-used assets | ||
| Machinery, equipment and vehicles | — | — | 
| Machinery, equipment and vehicles, net | 
                                                46,233,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                58,982,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Land | 
                                                6,080,942,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                6,080,942,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Leased assets | — | — | 
| Leased assets, net | 
                                                94,210,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                80,138,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Construction in progress | 
                                                128,312,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                23,154,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Property, plant and equipment | 
                                                9,993,533,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                9,776,855,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Intangible assets | 
                                                539,084,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                545,972,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Goodwill | 
                                                3,033,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                12,133,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Other | 
                                                536,051,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                533,838,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Intangible assets | ||
| Other intangible assets | ||
| Investments and other assets | ||
| Assets | 
                                                22,578,098,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                20,051,656,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Liabilities | ||
| Non-current liabilities | ||
| Long-term borrowings | 
                                                5,053,850,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                4,448,644,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Deferred tax liabilities | 
                                                108,903,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                185,180,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Lease liabilities | 
                                                124,942,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                115,089,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Retirement benefit liability | 
                                                432,890,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                441,669,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Provision for retirement benefits for directors (and other officers) | 
                                                152,141,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                142,370,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Other | 
                                                247,933,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                354,374,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Non-current liabilities | 
                                                7,032,632,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                6,690,246,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Asset retirement obligations | 
                                                349,405,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                351,974,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Current liabilities | ||
| Short-term borrowings | 
                                                3,704,248,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                3,622,200,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Notes and accounts payable - trade | 
                                                1,347,099,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                940,679,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Accounts payable - other | 
                                                361,432,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                321,709,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Income taxes payable | 
                                                192,861,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                100,338,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Lease liabilities | 
                                                33,919,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                36,693,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Current portion of long-term borrowings | 
                                                1,351,789,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,492,056,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Provisions | ||
| Provision for bonuses | 
                                                75,672,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                156,200,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Accrued expenses | 
                                                849,863,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                823,397,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Asset retirement obligations | 
                                                300,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                7,782,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Other | 
                                                472,068,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                422,138,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Current liabilities | 
                                                9,053,294,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                8,740,100,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Liabilities | 
                                                16,085,927,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                15,430,346,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Liabilities and net assets | ||
| Shareholders' equity | 
                                                6,444,332,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                4,592,061,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Share capital | 
                                                3,790,461,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                3,182,385,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Capital surplus | 
                                                3,080,174,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                2,472,098,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Retained earnings | 
                                                -413,949,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -1,052,073,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Treasury shares | 
                                                -12,353,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -10,349,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Valuation and translation adjustments | 
                                                47,838,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                29,248,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Valuation difference on available-for-sale securities | 
                                                35,988,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                19,815,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Foreign currency translation adjustment | 
                                                14,029,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                11,434,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Net assets | 
                                                6,492,170,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                4,621,309,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Liabilities and net assets | 
                                                22,578,098,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                20,051,656,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Net assets | ||
| Shareholders' equity | ||
| Valuation and translation adjustments | ||
| Remeasurements of defined benefit plans | 
                                                -2,179,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -2,002,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             |