Consolidated Statement Of Cash Flows
| Concept | 2023-04-01 to 2023-12-31 | As at 2023-12-31 | 2023-04-01 to 2023-12-31 | 2023-04-01 to 2023-12-31 | 2023-04-01 to 2023-12-31 | 2023-04-01 to 2023-12-31 | 2023-04-01 to 2023-12-31 | 2023-04-01 to 2023-12-31 | 2023-04-01 to 2023-12-31 | 2023-04-01 to 2023-12-31 | 2023-04-01 to 2023-12-31 | 2023-10-01 to 2023-12-31 | As at 2023-03-31 | As at 2022-12-31 | 2022-04-01 to 2022-12-31 | 2022-10-01 to 2022-12-31 | 2022-04-01 to 2022-12-31 | 2022-04-01 to 2022-12-31 | 2022-04-01 to 2022-12-31 | 2022-04-01 to 2022-12-31 | 2022-04-01 to 2022-12-31 | 2022-04-01 to 2022-12-31 | 2022-04-01 to 2022-12-31 | 2022-04-01 to 2022-12-31 | 2022-04-01 to 2022-12-31 | As at 2022-03-31 | 
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Consolidated statement of cash flows | ||||||||||||||||||||||||||
| Statement of cash flows | ||||||||||||||||||||||||||
| Cash flows from operating activities | ||||||||||||||||||||||||||
| Profit (loss) | 
                                                1,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                24,002,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                24,002,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                24,004,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                7,827,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                22,681,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                7,453,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                7,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                22,674,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                22,674,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Depreciation and amortization | — | — | — | — | — | — | — | — | — | — | 
                                                3,695,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                3,679,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | 
| Decrease (increase) in inventories | — | — | — | — | — | — | — | — | — | — | 
                                                -2,433,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                776,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | 
| Increase (decrease) in retirement benefit liability | — | — | — | — | — | — | — | — | — | — | 
                                                -617,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                -502,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | 
| Other | — | — | — | — | — | — | — | — | — | — | 
                                                -4,506,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                -1,023,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | 
| Subtotal | — | — | — | — | — | — | — | — | — | — | 
                                                19,311,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                19,258,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | 
| Interest paid | — | — | — | — | — | — | — | — | — | — | 
                                                -31,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                -31,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | 
| Income taxes paid | — | — | — | — | — | — | — | — | — | — | 
                                                -11,769,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                -7,142,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | 
| Net cash provided by (used in) operating activities | — | — | — | — | — | — | — | — | — | — | 
                                                8,126,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                12,618,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | 
| Cash flows from investing activities | ||||||||||||||||||||||||||
| Purchase of property, plant and equipment | — | — | — | — | — | — | — | — | — | — | 
                                                -2,635,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                -4,354,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | 
| Purchase of intangible assets | — | — | — | — | — | — | — | — | — | — | 
                                                -1,833,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                -1,176,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | 
| Other | — | — | — | — | — | — | — | — | — | — | 
                                                6,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                8,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | 
| Net cash provided by (used in) investing activities | — | — | — | — | — | — | — | — | — | — | 
                                                -2,654,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                -9,421,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | 
| Cash flows from financing activities | ||||||||||||||||||||||||||
| Purchase of treasury shares | — | — | — | — | — | — | — | — | — | — | 
                                                0
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                0
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | 
| Dividends paid | — | — | — | — | — | — | — | — | — | — | 
                                                -7,785,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                -7,599,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | 
| Net cash provided by (used in) financing activities | — | — | — | — | — | — | — | — | — | — | 
                                                -9,046,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                -8,922,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | 
| Cash and cash equivalents | — | 
                                                57,323,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | 
                                                60,047,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                54,919,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | 
                                                60,566,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Effect of exchange rate changes on cash and cash equivalents | — | — | — | — | — | — | — | — | — | — | 
                                                849,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                78,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — |