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 | 2023-10-01 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 | As at 2022-03-31 | 
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Consolidated statement of cash flows | ||||||||||||||||||||||
| Statement of cash flows | ||||||||||||||||||||||
| Cash flows from operating activities | ||||||||||||||||||||||
| Profit (loss) | 
                                                6,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -475,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -475,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -469,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -85,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                7,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                37,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                7,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                7,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Depreciation and amortization | — | — | — | — | — | — | — | — | 
                                                175,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                139,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | 
| Finance income | — | — | — | — | — | — | — | — | 
                                                0
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                0
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | 
| Finance costs | — | — | — | — | — | — | — | — | 
                                                33,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                35,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | 
| Share of loss (profit) of investments accounted for using equity method | — | — | — | — | — | — | — | — | 
                                                0
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                0
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | 
| Decrease (increase) in inventories | — | — | — | — | — | — | — | — | 
                                                14,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                -50,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | 
| Other | — | — | — | — | — | — | — | — | 
                                                -2,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                53,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | 
| Subtotal | — | — | — | — | — | — | — | — | 
                                                65,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                214,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | 
| Interest received | — | — | — | — | — | — | — | — | 
                                                0
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                0
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | 
| Interest paid | — | — | — | — | — | — | — | — | 
                                                -30,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                -32,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | 
| Net cash provided by (used in) operating activities | — | — | — | — | — | — | — | — | 
                                                -75,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                188,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | 
| Cash flows from investing activities | ||||||||||||||||||||||
| Payments for acquisition of subsidiaries | — | — | — | — | — | — | — | — | 
                                                -3,345,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                -23,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | 
| Other | — | — | — | — | — | — | — | — | 
                                                -31,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                -26,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | 
| Net cash provided by (used in) investing activities | — | — | — | — | — | — | — | — | 
                                                -2,373,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                -70,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | 
| Cash flows from financing activities | ||||||||||||||||||||||
| Net increase (decrease) in short-term borrowings | — | — | — | — | — | — | — | — | 
                                                -39,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | 
| Proceeds from long-term borrowings | — | — | — | — | — | — | — | — | 
                                                1,800,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                650,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | 
| Repayments of long-term borrowings | — | — | — | — | — | — | — | — | 
                                                -554,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                -351,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | 
| Proceeds from issuance of shares | — | — | — | — | — | — | — | — | 
                                                2,388,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | 
| Other | — | — | — | — | — | — | — | — | 
                                                2,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | 
| Net cash provided by (used in) financing activities | — | — | — | — | — | — | — | — | 
                                                3,562,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                9,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | 
| Cash and cash equivalents | — | 
                                                2,740,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | 
                                                1,627,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,498,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | 
                                                1,370,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             |