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 | 
                                                -303,254,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -250,913,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                430,597,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                308,891,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Depreciation | — | — | 
                                                408,562,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                455,243,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Impairment losses | — | — | 
                                                607,482,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Increase (decrease) in allowance for doubtful accounts | — | — | 
                                                -3,158,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -11,223,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Interest and dividend income | — | — | 
                                                -67,142,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -55,416,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Interest expenses | — | — | 
                                                23,772,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                15,513,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Increase (decrease) in retirement benefit liability | — | — | 
                                                59,583,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                20,861,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Increase (decrease) in provision for bonuses | — | — | 
                                                -51,317,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                8,760,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Loss (gain) on sale of property, plant and equipment | — | — | 
                                                -19,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -81,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Decrease (increase) in trade receivables | — | — | 
                                                1,799,851,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -1,019,559,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Subtotal | — | — | 
                                                970,240,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                475,687,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Income taxes paid | — | — | 
                                                -117,516,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -128,612,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Decrease (increase) in inventories | — | — | 
                                                118,247,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -183,589,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Increase (decrease) in trade payables | — | — | 
                                                -692,072,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                846,805,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Net cash provided by (used in) operating activities | — | — | 
                                                896,171,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                386,892,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Other, net | — | — | 
                                                -152,656,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                85,834,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Interest and dividends received | — | — | 
                                                67,142,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                55,416,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Interest paid | — | — | 
                                                -23,953,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -15,598,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Cash flows from investing activities | |||||||
| Payments into time deposits | — | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -5,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Purchase of property, plant and equipment | — | — | 
                                                -378,285,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -757,983,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Proceeds from sale of property, plant and equipment | — | — | 
                                                22,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                90,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Net cash provided by (used in) investing activities | — | — | 
                                                640,144,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -680,173,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Purchase of investment securities | — | — | 
                                                -7,029,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -6,747,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Proceeds from sale of investment securities | — | — | 
                                                1,038,899,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                117,620,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Other, net | — | — | 
                                                -2,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -8,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Cash flows from financing activities | |||||||
| Proceeds from short-term borrowings | — | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                400,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Purchase of treasury shares | — | — | 
                                                -45,218,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -14,421,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Repayments of short-term borrowings | — | — | 
                                                -200,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Proceeds from long-term borrowings | — | — | 
                                                1,100,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,000,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Dividends paid | — | — | 
                                                -94,839,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -94,783,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Dividends paid to non-controlling interests | — | — | 
                                                -19,417,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Repayments of long-term borrowings | — | — | 
                                                -1,012,927,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -1,016,091,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Net cash provided by (used in) financing activities | — | — | 
                                                -277,147,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                269,956,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Repayments of lease liabilities | — | — | 
                                                -4,754,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -4,754,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Net increase (decrease) in cash and cash equivalents | — | — | 
                                                1,259,167,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -23,324,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Cash and cash equivalents | — | 
                                                1,896,368,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                637,200,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                660,525,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             |