Quarterly Consolidated Statement Of Cash Flows
| Concept | 2024-04-01 to 2025-03-31 | As at 2025-03-31 | As at 2024-03-31 | 2023-04-01 to 2024-03-31 | As at 2023-03-31 | 
|---|---|---|---|---|---|
| Quarterly consolidated statement of cash flows | |||||
| Statement of cash flows | |||||
| Cash flows from operating activities | |||||
| Profit (loss) before income taxes | 
                                                1,013,247,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                618,081,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Depreciation | 
                                                539,826,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                608,035,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Impairment losses | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                152,526,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Increase (decrease) in allowance for doubtful accounts | 
                                                -9,854,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                3,786,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Interest and dividend income | 
                                                -3,767,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -2,131,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Decrease (increase) in inventories | 
                                                -29,521,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                8,320,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Increase (decrease) in trade payables | 
                                                24,316,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -238,604,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Other, net | 
                                                3,284,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -6,898,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Subtotal | 
                                                1,999,925,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                1,370,901,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Interest and dividends received | 
                                                3,767,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                2,131,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Income taxes paid | 
                                                -261,664,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -181,552,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Net cash provided by (used in) operating activities | 
                                                1,742,029,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                1,191,479,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Cash flows from investing activities | |||||
| Purchase of property, plant and equipment | 
                                                -306,996,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -511,085,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Proceeds from sale of property, plant and equipment | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                92,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Other, net | 
                                                69,909,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                18,971,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Net cash provided by (used in) investing activities | 
                                                -2,147,049,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -523,035,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Cash flows from financing activities | |||||
| Purchase of treasury shares | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -50,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Dividends paid | 
                                                -283,296,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -283,099,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Net cash provided by (used in) financing activities | 
                                                -287,804,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -286,137,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Net increase (decrease) in cash and cash equivalents | 
                                                -692,824,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                382,307,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Cash and cash equivalents | — | 
                                                3,406,571,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                4,099,395,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                3,717,088,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             |