Notes - Segment Information
| Concept | 2023-10-01 to 2024-09-30 | As at 2024-09-30 | 2023-10-01 to 2024-09-30 | 2023-10-01 to 2024-09-30 | 2023-10-01 to 2024-09-30 | 2023-10-01 to 2024-09-30 | 2023-10-01 to 2024-09-30 | 2022-10-01 to 2023-09-30 | As at 2023-09-30 | 2022-10-01 to 2023-09-30 | 2022-10-01 to 2023-09-30 | 2022-10-01 to 2023-09-30 | 2022-10-01 to 2023-09-30 | 2022-10-01 to 2023-09-30 | 
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Notes - Segment information | ||||||||||||||
| Segment information | ||||||||||||||
| Revenue | ||||||||||||||
| Revenue from external customers | 
                                                24,024,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                34,466,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                8,154,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                34,466,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                2,288,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                8,252,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                4,926,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                36,405,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                36,405,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                23,226,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Intersegment revenue | 
                                                9,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                9,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -9,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                6,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                6,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -6,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Revenue | 
                                                24,034,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                34,466,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                8,154,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                34,476,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -9,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                2,288,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                8,252,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                4,926,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                36,412,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                36,405,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                23,232,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -6,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Segment profit (loss) | 
                                                2,673,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                820,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -1,464,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                787,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                33,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -421,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -246,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -204,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                2,326,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                2,340,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                2,778,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                13,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Other income and expenses, net | — | — | 
                                                -7,263,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | 
                                                -497,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Finance income and costs, net | — | — | 
                                                -178,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | 
                                                -127,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Share of profit (loss) of investments accounted for using equity method | — | — | 
                                                -193,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | 
                                                -197,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Profit (loss) before tax | — | — | 
                                                -7,076,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | 
                                                1,518,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Assets | — | 
                                                41,191,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | 
                                                51,166,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
| Investments accounted for using equity method | — | 
                                                205,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | 
                                                536,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
| Depreciation and amortization | 
                                                1,060,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                1,957,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                849,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,957,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                47,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                895,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                90,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                2,081,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                2,081,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,095,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Impairment losses | — | — | 
                                                7,081,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | 
                                                128,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — |