Quarterly Consolidated Statement Of Cash Flows
| Concept | As at 2024-12-31 | 2024-07-01 to 2024-12-31 | As at 2024-06-30 | As at 2023-12-31 | 2023-07-01 to 2023-12-31 | As at 2023-06-30 | 
|---|---|---|---|---|---|---|
| Quarterly consolidated statement of cash flows | ||||||
| Statement of cash flows | ||||||
| Cash flows from operating activities | ||||||
| Subtotal | — | 
                                                -1,581,079,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -1,666,484,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Interest and dividends received | — | 
                                                415,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                1,143,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Interest paid | — | 
                                                -3,502,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -3,974,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Income taxes paid | — | 
                                                -342,400,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -255,913,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Net cash provided by (used in) operating activities | — | 
                                                -1,912,954,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -1,911,494,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Cash flows from investing activities | ||||||
| Purchase of property, plant and equipment | — | 
                                                -141,901,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -135,306,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Proceeds from sale of property, plant and equipment | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                15,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Purchase of investment securities | — | 
                                                -20,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -10,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Loan advances | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -20,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Other, net | — | 
                                                845,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                8,341,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Net cash provided by (used in) investing activities | — | 
                                                -161,056,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -64,494,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Cash flows from financing activities | ||||||
| Proceeds from long-term borrowings | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                159,970,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Repayments of long-term borrowings | — | 
                                                -32,650,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Purchase of treasury shares | — | 
                                                -82,402,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -159,857,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Dividends paid | — | 
                                                -197,921,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -155,183,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Net cash provided by (used in) financing activities | — | 
                                                1,707,583,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                1,803,261,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Effect of exchange rate change on cash and cash equivalents | — | 
                                                -42,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -11,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Net increase (decrease) in cash and cash equivalents | — | 
                                                -366,469,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -172,738,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Cash and cash equivalents | 
                                                1,357,067,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                1,723,536,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,457,720,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                1,630,459,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             |