Consolidated Statement Of Cash Flows
| Concept | As at 2025-03-31 | 2024-04-01 to 2025-03-31 | 2023-04-01 to 2024-03-31 | As at 2024-03-31 | As at 2023-03-31 | 
|---|---|---|---|---|---|
| Consolidated statement of cash flows | |||||
| Statement of cash flows | |||||
| Cash flows from operating activities | |||||
| Subtotal | — | 
                                                1,152,911,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,771,379,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Interest paid | — | 
                                                -69,847,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -61,677,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Income taxes paid | — | 
                                                -731,849,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -515,258,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Net cash provided by (used in) operating activities | — | 
                                                331,049,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,785,929,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Cash flows from investing activities | |||||
| Purchase of property, plant and equipment | — | 
                                                -1,590,422,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -1,193,886,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Proceeds from sale of property, plant and equipment | — | 
                                                69,192,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Net cash provided by (used in) investing activities | — | 
                                                -249,560,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -1,361,859,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Purchase of investment securities | — | 
                                                -134,024,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -37,100,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Proceeds from sale of investment securities | — | 
                                                656,064,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Proceeds from sale of shares of subsidiaries resulting in change in scope of consolidation | — | 
                                                933,069,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Other, net | — | 
                                                -666,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -210,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Cash flows from financing activities | |||||
| Purchase of treasury shares | — | 
                                                -141,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -131,900,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Dividends paid | — | 
                                                -93,575,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -75,069,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Proceeds from long-term borrowings | — | 
                                                560,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,500,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Repayments of long-term borrowings | — | 
                                                -1,127,297,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -1,242,250,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Dividends paid to non-controlling interests | — | 
                                                -4,967,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -186,786,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Purchase of shares of subsidiaries not resulting in change in scope of consolidation | — | 
                                                -9,219,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Net cash provided by (used in) financing activities | — | 
                                                -667,603,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -116,145,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Other, net | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -5,862,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Effect of exchange rate change on cash and cash equivalents | — | 
                                                -202,390,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                186,602,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Net increase (decrease) in cash and cash equivalents | — | 
                                                -788,505,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                494,526,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Cash and cash equivalents | 
                                                5,152,618,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                5,941,124,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                5,446,597,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             |