Semi-Annual Consolidated Statement Of Cash Flows
| Concept | 2023-01-01 to 2023-12-31 | As at 2023-12-31 | 2022-01-01 to 2022-12-31 | As at 2022-12-31 | As at 2021-12-31 | 
|---|---|---|---|---|---|
| Semi-annual consolidated statement of cash flows | |||||
| Statement of cash flows | |||||
| Cash flows from operating activities | |||||
| Subtotal | 
                                                -360,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -1,140,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Interest and dividends received | 
                                                2,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                3,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Interest paid | 
                                                -10,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -20,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Income taxes paid | 
                                                -77,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -74,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Net cash provided by (used in) operating activities | 
                                                -445,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -44,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Cash flows from investing activities | |||||
| Purchase of property, plant and equipment | 
                                                -40,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -46,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Proceeds from sale of property, plant and equipment | 
                                                6,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                26,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Other, net | 
                                                2,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                17,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Net cash provided by (used in) investing activities | 
                                                -62,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -146,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Cash flows from financing activities | |||||
| Repayments of long-term borrowings | 
                                                -698,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -1,266,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Proceeds from issuance of shares | 
                                                1,954,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                27,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Net cash provided by (used in) financing activities | 
                                                740,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -2,275,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Other, net | 
                                                -3,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -27,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Effect of exchange rate change on cash and cash equivalents | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Net increase (decrease) in cash and cash equivalents | 
                                                233,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -2,467,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Cash and cash equivalents | — | 
                                                2,121,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                1,888,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                4,355,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             |