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 | 
                                                63,374,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                382,332,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                521,611,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                208,914,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Depreciation | — | — | 
                                                444,473,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                442,705,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Impairment losses | — | — | 
                                                98,425,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Amortization of goodwill | — | — | 
                                                17,535,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                16,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Increase (decrease) in allowance for doubtful accounts | — | — | 
                                                -374,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -595,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Interest and dividend income | — | — | 
                                                -11,659,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -8,320,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Interest expenses | — | — | 
                                                13,134,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                7,700,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Increase (decrease) in retirement benefit liability | — | — | 
                                                2,073,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -21,540,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Increase (decrease) in provision for bonuses | — | — | 
                                                -35,677,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -25,038,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Subtotal | — | — | 
                                                1,269,983,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,001,642,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Decrease (increase) in trade receivables | — | — | 
                                                443,304,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                427,871,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Decrease (increase) in inventories | — | — | 
                                                166,188,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                12,460,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Income taxes paid | — | — | 
                                                -166,288,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -123,177,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Net cash provided by (used in) operating activities | — | — | 
                                                1,115,194,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                956,971,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Increase (decrease) in trade payables | — | — | 
                                                -46,483,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -329,201,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Other, net | — | — | 
                                                22,374,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -42,862,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Loss (gain) on sale of non-current assets | — | — | 
                                                -1,470,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -153,621,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Interest and dividends received | — | — | 
                                                11,663,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                8,316,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Interest paid | — | — | 
                                                -13,386,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -7,792,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Cash flows from investing activities | |||||||
| Purchase of property, plant and equipment | — | — | 
                                                -307,596,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -820,311,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Proceeds from sale of property, plant and equipment | — | — | 
                                                1,627,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                497,785,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Net cash provided by (used in) investing activities | — | — | 
                                                -480,515,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -592,176,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Purchase of investment securities | — | — | 
                                                -4,723,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -4,031,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Proceeds from sale of investment securities | — | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,400,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Purchase of shares of subsidiaries resulting in change in scope of consolidation | — | — | 
                                                -40,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -155,520,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Loan advances | — | — | 
                                                -9,600,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -5,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Proceeds from collection of loans receivable | — | — | 
                                                220,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                11,251,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Cash flows from financing activities | |||||||
| Purchase of treasury shares | — | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -46,979,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Proceeds from long-term borrowings | — | — | 
                                                300,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                600,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Net increase (decrease) in short-term borrowings | — | — | 
                                                -93,684,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                418,209,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Dividends paid | — | — | 
                                                -134,370,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -135,138,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Dividends paid to non-controlling interests | — | — | 
                                                -12,034,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -13,877,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Repayments of long-term borrowings | — | — | 
                                                -190,909,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -356,224,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Net cash provided by (used in) financing activities | — | — | 
                                                -172,496,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                417,893,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Repayments of lease liabilities | — | — | 
                                                -41,498,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -48,095,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Effect of exchange rate change on cash and cash equivalents | — | — | 
                                                65,864,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                36,819,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Net increase (decrease) in cash and cash equivalents | — | — | 
                                                528,046,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                819,507,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Cash and cash equivalents | — | 
                                                3,435,902,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                2,911,687,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                2,092,180,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             |