Semi-Annual Consolidated Statement Of Cash Flows
| Concept | As at 2023-09-30 | 2023-04-01 to 2023-09-30 | As at 2023-03-31 | As at 2022-09-30 | 2022-04-01 to 2022-09-30 | As at 2022-03-31 | 
|---|---|---|---|---|---|---|
| Semi-annual consolidated statement of cash flows | ||||||
| Statement of cash flows | ||||||
| Cash flows from operating activities | ||||||
| Subtotal | — | 
                                                605,358,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                485,016,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Interest and dividends received | — | 
                                                41,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                8,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Interest paid | — | 
                                                -40,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -488,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Income taxes paid | — | 
                                                -197,418,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -105,499,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Net cash provided by (used in) operating activities | — | 
                                                407,941,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                371,350,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Cash flows from investing activities | ||||||
| Purchase of property, plant and equipment | — | 
                                                -2,932,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -55,726,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Purchase of investment securities | — | 
                                                -15,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Net cash provided by (used in) investing activities | — | 
                                                -29,252,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -31,765,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Cash flows from financing activities | ||||||
| Repayments of long-term borrowings | — | 
                                                -22,500,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -45,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Purchase of treasury shares | — | 
                                                -6,731,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Dividends paid | — | 
                                                -129,442,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -183,216,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Net cash provided by (used in) financing activities | — | 
                                                -156,273,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -225,516,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Effect of exchange rate change on cash and cash equivalents | — | 
                                                -29,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Net increase (decrease) in cash and cash equivalents | — | 
                                                222,384,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                114,068,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Cash and cash equivalents | 
                                                3,648,216,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                2,047,536,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,838,912,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                1,724,844,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             |