Semi-Annual Consolidated Balance Sheet
| Concept | As at 2023-12-31 | As at 2023-03-31 | 
|---|---|---|
| Semi-annual consolidated balance sheet | ||
| Balance sheet | ||
| Assets | ||
| Current assets | ||
| Cash and deposits | 
                                                2,075,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                2,234,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Inventories | 
                                                88,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                61,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Other | 
                                                1,141,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,000,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Allowance for doubtful accounts | 
                                                0
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                0
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Current assets | 
                                                9,310,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                9,543,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Non-current assets | ||
| Property, plant and equipment | 
                                                23,690,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                23,849,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Property, plant and equipment | ||
| Buildings and structures | — | — | 
| Buildings and structures, net | 
                                                4,402,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                4,372,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Machinery, equipment and vehicles | — | — | 
| Machinery, equipment and vehicles, net | 
                                                2,067,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                2,262,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Land | 
                                                16,853,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                16,840,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Other | — | — | 
| Other, net | 
                                                367,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                374,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Intangible assets | ||
| Other | 
                                                91,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                88,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Intangible assets | 
                                                922,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,175,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Investments and other assets | 
                                                3,247,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                3,116,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Investments and other assets | ||
| Investment securities | 
                                                2,559,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                2,321,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Deferred tax assets | 
                                                75,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                187,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Other | 
                                                734,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                731,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Allowance for doubtful accounts | 
                                                -122,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -123,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Non-current assets | 
                                                27,859,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                28,141,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Assets | 
                                                37,169,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                37,685,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Liabilities | ||
| Current liabilities | ||
| Short-term borrowings | 
                                                1,590,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,444,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Income taxes payable | 
                                                45,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                171,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Other | 
                                                2,878,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                2,499,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Current liabilities | 
                                                7,408,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                7,545,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Non-current liabilities | ||
| Long-term borrowings | 
                                                490,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,070,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Retirement benefit liability | 
                                                2,227,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                2,232,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Asset retirement obligations | 
                                                69,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                69,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Other | 
                                                447,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                344,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Non-current liabilities | 
                                                5,121,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                5,660,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Liabilities | 
                                                12,530,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                13,205,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Provision for bonuses | 
                                                356,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                665,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Deferred tax liabilities for land revaluation | 
                                                1,886,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,886,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Net assets | ||
| Shareholders' equity | ||
| Share capital | 
                                                3,559,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                3,559,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Capital surplus | 
                                                3,067,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                3,087,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Retained earnings | 
                                                13,727,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                13,705,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Treasury shares | 
                                                -22,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -22,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Shareholders' equity | 
                                                20,331,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                20,329,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Valuation and translation adjustments | ||
| Valuation difference on available-for-sale securities | 
                                                1,068,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                904,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Revaluation reserve for land | 
                                                2,901,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                2,901,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Foreign currency translation adjustment | 
                                                98,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                71,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Remeasurements of defined benefit plans | 
                                                -26,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -40,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Valuation and translation adjustments | 
                                                4,042,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                3,836,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Non-controlling interests | 
                                                265,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                313,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Net assets | 
                                                24,639,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                24,479,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Liabilities and net assets | 
                                                37,169,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                37,685,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             |