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 | ||||||
| Subtotal | — | 
                                                -860,828,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -40,444,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Interest and dividends received | — | 
                                                35,550,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                15,730,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Interest paid | — | 
                                                -9,548,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -1,823,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Income taxes paid | — | 
                                                -364,495,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -673,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Net cash provided by (used in) operating activities | — | 
                                                -1,155,400,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                3,816,820,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Cash flows from investing activities | ||||||
| Purchase of property, plant and equipment | — | 
                                                -52,067,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -87,435,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Purchase of investment securities | — | 
                                                -11,900,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Net cash provided by (used in) investing activities | — | 
                                                -124,428,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -3,495,276,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Other, net | — | 
                                                -53,697,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                5,593,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Cash flows from financing activities | ||||||
| Purchase of treasury shares | — | 
                                                -169,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -903,099,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Dividends paid | — | 
                                                -889,538,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -452,648,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Repayments of long-term borrowings | — | 
                                                -23,944,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -30,261,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Net cash provided by (used in) financing activities | — | 
                                                918,372,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -1,385,180,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Other, net | — | 
                                                -2,854,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -2,097,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Effect of exchange rate change on cash and cash equivalents | — | 
                                                -1,677,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                21,974,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Net increase (decrease) in cash and cash equivalents | — | 
                                                -363,134,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -1,041,662,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Cash and cash equivalents | 
                                                1,156,755,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                1,519,890,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,892,432,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                2,934,094,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             |