Consolidated Statement Of Cash Flows
| Concept | As at 2024-09-30 | 2024-04-01 to 2024-09-30 | As at 2024-03-31 | As at 2023-09-30 | 2023-04-01 to 2023-09-30 | As at 2023-03-31 | 
|---|---|---|---|---|---|---|
| Consolidated statement of cash flows | ||||||
| Statement of cash flows | ||||||
| Cash flows from operating activities | ||||||
| Profit (loss) before income taxes | — | 
                                                8,426,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                8,619,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Depreciation | — | 
                                                150,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                170,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Impairment losses | — | 
                                                620,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                3,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Increase (decrease) in allowance for doubtful accounts | — | 
                                                4,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                4,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Interest and dividend income | — | 
                                                -5,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                0
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Increase (decrease) in retirement benefit liability | — | 
                                                186,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                285,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Increase (decrease) in provision for bonuses | — | 
                                                70,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -10,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Decrease (increase) in trade receivables | — | 
                                                114,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -523,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Subtotal | — | 
                                                7,296,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                7,782,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Income taxes paid | — | 
                                                -3,676,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -2,814,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Decrease (increase) in inventories | — | 
                                                -92,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -53,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Net cash provided by (used in) operating activities | — | 
                                                3,683,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                4,986,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Other, net | — | 
                                                91,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                102,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Interest and dividends received | — | 
                                                5,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                0
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Cash flows from investing activities | ||||||
| Purchase of property, plant and equipment | — | 
                                                0
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -21,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Net cash provided by (used in) investing activities | — | 
                                                -467,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -506,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Cash flows from financing activities | ||||||
| Purchase of treasury shares | — | 
                                                0
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                0
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Dividends paid | — | 
                                                -5,399,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -4,934,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Net cash provided by (used in) financing activities | — | 
                                                -5,399,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -4,935,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Net increase (decrease) in cash and cash equivalents | — | 
                                                -2,183,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -456,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Cash and cash equivalents | 
                                                50,561,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                52,744,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                50,572,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                51,028,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             |