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 | — | 
                                                1,163,655,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                925,203,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Interest and dividends received | — | 
                                                20,529,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                5,749,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Interest paid | — | 
                                                -5,561,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -3,701,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Income taxes paid | — | 
                                                -358,587,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -365,911,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Net cash provided by (used in) operating activities | — | 
                                                820,036,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                561,340,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Cash flows from investing activities | ||||||
| Purchase of property, plant and equipment | — | 
                                                -620,507,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -94,578,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Proceeds from sale of property, plant and equipment | — | 
                                                1,579,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                1,019,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Purchase of investment securities | — | 
                                                -85,137,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -2,079,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Net cash provided by (used in) investing activities | — | 
                                                -327,990,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -1,550,348,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Proceeds from sale of investment securities | — | 
                                                391,744,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                1,211,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Purchase of shares of subsidiaries resulting in change in scope of consolidation | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -1,504,230,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Loan advances | — | 
                                                -825,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -25,079,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Proceeds from collection of loans receivable | — | 
                                                562,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                15,317,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Cash flows from financing activities | ||||||
| Dividends paid | — | 
                                                -269,161,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -236,445,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Proceeds from long-term borrowings | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                1,990,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Repayments of long-term borrowings | — | 
                                                -167,415,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -235,274,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Redemption of bonds | — | 
                                                -5,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -100,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Dividends paid to non-controlling interests | — | 
                                                -162,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -150,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Net cash provided by (used in) financing activities | — | 
                                                -594,656,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                1,265,814,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Other, net | — | 
                                                -2,918,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -2,316,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Effect of exchange rate change on cash and cash equivalents | — | 
                                                20,971,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                26,899,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Net increase (decrease) in cash and cash equivalents | — | 
                                                -81,639,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                303,705,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Cash and cash equivalents | 
                                                3,136,859,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                3,213,159,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                2,603,626,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                2,299,921,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             |