Quarterly Consolidated Balance Sheet
| Concept | As at 2023-09-30 | As at 2023-03-31 | 
|---|---|---|
| Quarterly consolidated balance sheet | ||
| Balance sheet | ||
| Assets | ||
| Current assets | ||
| Cash and deposits | 
                                                5,579,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                5,482,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Other | 
                                                303,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                387,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Allowance for doubtful accounts | 
                                                -80,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -82,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Current assets | 
                                                13,813,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                13,797,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Non-current assets | ||
| Property, plant and equipment | 
                                                3,196,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                3,240,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Property, plant and equipment | ||
| Land | 
                                                1,592,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,592,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Other | — | — | 
| Other, net | 
                                                103,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                111,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Intangible assets | ||
| Intangible assets | 
                                                519,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                422,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Investments and other assets | 
                                                913,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                893,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Investments and other assets | ||
| Other | 
                                                938,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                919,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Allowance for doubtful accounts | 
                                                -25,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -25,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Non-current assets | 
                                                4,629,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                4,557,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Assets | 
                                                18,443,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                18,354,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Liabilities | ||
| Current liabilities | ||
| Income taxes payable | 
                                                112,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                117,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Other | 
                                                770,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                596,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Current liabilities | 
                                                5,908,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                5,931,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Non-current liabilities | ||
| Asset retirement obligations | 
                                                45,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                45,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Other | 
                                                437,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                368,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Non-current liabilities | 
                                                1,530,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,471,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Liabilities | 
                                                7,438,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                7,402,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Net assets | ||
| Shareholders' equity | ||
| Share capital | 
                                                1,581,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,581,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Capital surplus | 
                                                395,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                395,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Retained earnings | 
                                                8,984,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                8,954,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Treasury shares | 
                                                -7,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -7,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Shareholders' equity | 
                                                10,952,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                10,923,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Valuation and translation adjustments | ||
| Valuation difference on available-for-sale securities | 
                                                51,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                28,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Valuation and translation adjustments | 
                                                51,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                28,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Net assets | 
                                                11,004,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                10,951,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Liabilities and net assets | 
                                                18,443,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                18,354,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             |