Semi-Annual Consolidated Statement Of Cash Flows
| Concept | 2024-04-01 to 2024-09-30 | As at 2024-09-30 | As at 2024-03-31 | 2023-04-01 to 2023-09-30 | As at 2023-09-30 | As at 2023-03-31 | 
|---|---|---|---|---|---|---|
| Semi-annual consolidated statement of cash flows | ||||||
| Statement of cash flows | ||||||
| Cash flows from operating activities | ||||||
| Subtotal | 
                                                306,846,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                502,585,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Interest and dividends received | 
                                                34,242,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                8,442,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Net cash provided by (used in) operating activities | 
                                                261,970,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                292,324,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Cash flows from investing activities | ||||||
| Purchase of property, plant and equipment | 
                                                -77,217,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -175,704,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Purchase of investment securities | 
                                                -1,562,407,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Other, net | 
                                                -460,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Net cash provided by (used in) investing activities | 
                                                -1,640,084,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -195,236,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Cash flows from financing activities | ||||||
| Purchase of treasury shares | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -63,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Dividends paid | 
                                                -173,975,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -197,928,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Net cash provided by (used in) financing activities | 
                                                -173,975,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -197,991,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Effect of exchange rate change on cash and cash equivalents | 
                                                -26,439,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                47,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Net increase (decrease) in cash and cash equivalents | 
                                                -1,578,528,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -100,856,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Cash and cash equivalents | — | 
                                                3,739,455,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                5,317,984,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                5,483,575,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                5,584,431,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             |