Quarterly Statement Of Cash Flows
| Concept | 2023-04-01 to 2024-03-31 | As at 2024-03-31 | As at 2023-03-31 | 2022-04-01 to 2023-03-31 | As at 2022-03-31 | 
|---|---|---|---|---|---|
| Quarterly statement of cash flows | |||||
| Statement of cash flows | |||||
| Cash flows from operating activities | |||||
| Subtotal | 
                                                1,396,810,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                965,637,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Interest and dividends received | 
                                                59,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                16,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Interest paid | 
                                                -40,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -752,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Income taxes paid | 
                                                -359,179,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -205,510,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Net cash provided by (used in) operating activities | 
                                                1,033,142,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                748,458,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Cash flows from investing activities | |||||
| Purchase of property, plant and equipment | 
                                                -4,758,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -63,987,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Purchase of investment securities | 
                                                -15,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -20,900,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Net cash provided by (used in) investing activities | 
                                                -68,311,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -82,049,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Cash flows from financing activities | |||||
| Repayments of long-term borrowings | 
                                                -22,500,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -90,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Purchase of treasury shares | 
                                                -10,059,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -84,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Dividends paid | 
                                                -294,192,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -274,932,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Net cash provided by (used in) financing activities | 
                                                -301,252,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -343,716,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Effect of exchange rate change on cash and cash equivalents | 
                                                -29,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Net increase (decrease) in cash and cash equivalents | 
                                                663,548,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                322,692,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Cash and cash equivalents | — | 
                                                4,089,380,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                2,047,536,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                1,724,844,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             |