Consolidated Statement Of Changes In Equity
| Concept | As at 2024-03-31 | 2023-10-01 to 2024-03-31 | As at 2024-03-31 | 2024-01-01 to 2024-03-31 | As at 2024-03-31 | 2023-10-01 to 2024-03-31 | 2023-10-01 to 2024-03-31 | 2023-10-01 to 2024-03-31 | As at 2024-03-31 | 2023-10-01 to 2024-03-31 | 2023-10-01 to 2024-03-31 | 2023-10-01 to 2024-03-31 | As at 2024-03-31 | As at 2024-03-31 | As at 2024-03-31 | 2023-10-01 to 2024-03-31 | As at 2024-03-31 | As at 2023-09-30 | As at 2023-09-30 | As at 2023-09-30 | As at 2023-09-30 | As at 2023-09-30 | As at 2023-09-30 | As at 2023-09-30 | As at 2023-09-30 | 2023-01-01 to 2023-03-31 | As at 2023-03-31 | 2022-10-01 to 2023-03-31 | 2022-10-01 to 2023-03-31 | 2022-10-01 to 2023-03-31 | 2022-10-01 to 2023-03-31 | 2022-10-01 to 2023-03-31 | 2022-10-01 to 2023-03-31 | 2022-10-01 to 2023-03-31 | As at 2023-03-31 | 2022-10-01 to 2023-03-31 | As at 2023-03-31 | As at 2023-03-31 | As at 2023-03-31 | As at 2023-03-31 | As at 2023-03-31 | As at 2023-03-31 | As at 2022-09-30 | As at 2022-09-30 | As at 2022-09-30 | As at 2022-09-30 | As at 2022-09-30 | As at 2022-09-30 | As at 2022-09-30 | As at 2022-09-30 | 
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Consolidated statement of changes in equity | ||||||||||||||||||||||||||||||||||||||||||||||||||
| Statement of changes in equity | ||||||||||||||||||||||||||||||||||||||||||||||||||
| Equity | 
                                                9,716,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                9,962,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                93,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                3,608,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                -2,009,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                32,514,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                32,607,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                11,236,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -2,009,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                97,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                10,035,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                3,051,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                11,662,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                9,716,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                32,456,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                32,554,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                11,801,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | 
                                                9,716,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                10,085,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                31,224,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,518,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                31,112,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -2,009,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                111,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                10,033,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,233,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                11,018,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                31,123,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                9,716,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                30,991,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -1,009,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                131,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Comprehensive income | ||||||||||||||||||||||||||||||||||||||||||||||||||
| Profit (loss) | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                515,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                119,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                119,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -3,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                115,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | 
                                                596,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,124,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,124,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                39,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                1,164,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | — | — | — | 
| Other comprehensive income | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                731,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                557,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                557,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                557,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | 
                                                622,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                234,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                234,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                234,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | — | — | — | 
| Comprehensive income | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                1,247,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                557,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                676,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                119,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -3,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                672,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | 
                                                1,218,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                234,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,358,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,124,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                39,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                1,398,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | — | — | — | 
| Transactions with owners | ||||||||||||||||||||||||||||||||||||||||||||||||||
| Purchase of treasury shares | — | 
                                                0
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                0
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                0
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | 
                                                -1,000,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -1,000,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -1,000,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | — | — | — | 
| Dividends | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -545,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -545,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -1,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                -547,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -296,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -296,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -59,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -356,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | — | — | — | 
| Share-based payment transactions | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                0
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -21,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -21,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                -21,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                6,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                58,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                52,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                58,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | — | — | — | 
| Total transactions with owners | — | 
                                                0
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                0
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -618,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -545,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -73,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -1,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                -619,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | 
                                                -1,000,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                50,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -1,238,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -341,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                52,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -59,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -1,297,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | — | — | — |