Consolidated Statement Of Cash Flows
| Concept | 2024-04-01 to 2025-03-31 | As at 2025-03-31 | 2024-04-01 to 2025-03-31 | 2023-04-01 to 2024-03-31 | As at 2024-03-31 | 2023-04-01 to 2024-03-31 | As at 2023-03-31 | 
|---|---|---|---|---|---|---|---|
| Consolidated statement of cash flows | |||||||
| Statement of cash flows | |||||||
| Cash flows from operating activities | |||||||
| Profit (loss) before income taxes | 
                                                4,154,594,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                6,886,519,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                7,275,968,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                5,148,138,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Depreciation | — | — | 
                                                1,109,637,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,135,697,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Increase (decrease) in allowance for doubtful accounts | — | — | 
                                                -16,773,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -8,395,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Interest and dividend income | — | — | 
                                                -177,429,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -172,384,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Interest expenses | — | — | 
                                                57,505,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                12,461,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Increase (decrease) in retirement benefit liability | — | — | 
                                                100,440,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                65,636,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Share of loss (profit) of entities accounted for using equity method | — | — | 
                                                -158,842,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -103,545,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Decrease (increase) in trade receivables | — | — | 
                                                2,418,282,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                252,506,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Subtotal | — | — | 
                                                6,455,777,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                5,806,517,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Income taxes paid | — | — | 
                                                -2,674,981,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -2,113,652,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Decrease (increase) in inventories | — | — | 
                                                -1,339,785,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -1,459,996,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Increase (decrease) in trade payables | — | — | 
                                                -2,477,575,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -956,536,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Net cash provided by (used in) operating activities | — | — | 
                                                3,910,247,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                3,970,011,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Other, net | — | — | 
                                                -379,601,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -70,457,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Interest and dividends received | — | — | 
                                                177,429,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                290,509,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Interest paid | — | — | 
                                                -47,978,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -13,363,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Cash flows from investing activities | |||||||
| Payments into time deposits | — | — | 
                                                -630,335,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -630,295,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Proceeds from withdrawal of time deposits | — | — | 
                                                630,300,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                630,289,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Purchase of property, plant and equipment | — | — | 
                                                -852,352,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -2,073,141,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Proceeds from sale of property, plant and equipment | — | — | 
                                                1,353,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                8,088,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Purchase of investment securities | — | — | 
                                                -933,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -860,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Net cash provided by (used in) investing activities | — | — | 
                                                -1,084,444,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -2,757,913,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Proceeds from sale of investment securities | — | — | 
                                                17,860,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                9,981,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Proceeds from collection of loans receivable | — | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                500,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Cash flows from financing activities | |||||||
| Purchase of treasury shares | — | — | 
                                                -1,043,620,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -1,026,693,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Dividends paid | — | — | 
                                                -1,608,767,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -1,427,878,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Proceeds from issuance of bonds | — | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                100,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Proceeds from long-term borrowings | — | — | 
                                                7,000,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                255,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Dividends paid to non-controlling interests | — | — | 
                                                -4,864,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -5,244,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Redemption of bonds | — | — | 
                                                -93,400,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -76,700,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Repayments of long-term borrowings | — | — | 
                                                -279,369,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -260,083,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Net cash provided by (used in) financing activities | — | — | 
                                                4,371,583,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -2,489,006,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Repayments of lease liabilities | — | — | 
                                                -95,713,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -93,484,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Effect of exchange rate change on cash and cash equivalents | — | — | 
                                                393,842,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                92,238,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Net increase (decrease) in cash and cash equivalents | — | — | 
                                                7,591,228,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -1,184,669,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Cash and cash equivalents | — | 
                                                18,915,664,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                11,324,435,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                12,509,105,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             |