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 | 
                                                -25,834,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                211,770,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                73,576,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                128,316,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Depreciation | — | — | 
                                                7,308,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                4,534,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Impairment losses | — | — | 
                                                4,258,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Increase (decrease) in allowance for doubtful accounts | — | — | 
                                                -43,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                98,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Interest and dividend income | — | — | 
                                                -347,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -53,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Interest expenses | — | — | 
                                                8,872,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                14,085,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Increase (decrease) in retirement benefit liability | — | — | 
                                                5,733,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                5,182,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Decrease (increase) in trade receivables | — | — | 
                                                51,689,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                41,648,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Subtotal | — | — | 
                                                202,625,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                260,019,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Income taxes paid | — | — | 
                                                -3,259,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -1,624,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Decrease (increase) in inventories | — | — | 
                                                -4,051,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -1,248,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Increase (decrease) in trade payables | — | — | 
                                                -100,880,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                89,496,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Net cash provided by (used in) operating activities | — | — | 
                                                190,680,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                244,637,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Other, net | — | — | 
                                                -4,996,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -23,205,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Loss (gain) on sale of non-current assets | — | — | 
                                                0
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Interest and dividends received | — | — | 
                                                176,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                53,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Interest paid | — | — | 
                                                -8,869,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -13,815,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Cash flows from investing activities | |||||||
| Payments into time deposits | — | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -102,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Proceeds from withdrawal of time deposits | — | — | 
                                                100,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                150,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Purchase of property, plant and equipment | — | — | 
                                                -10,858,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -1,318,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Net cash provided by (used in) investing activities | — | — | 
                                                43,620,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                22,769,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Purchase of investment securities | — | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -20,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Cash flows from financing activities | |||||||
| Proceeds from issuance of shares | — | — | 
                                                163,585,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                15,197,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Net increase (decrease) in short-term borrowings | — | — | 
                                                -180,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -370,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Dividends paid | — | — | 
                                                -21,373,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -14,474,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Proceeds from issuance of bonds | — | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                200,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Proceeds from long-term borrowings | — | — | 
                                                50,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Repayments of long-term borrowings | — | — | 
                                                -96,801,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -109,292,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Redemption of bonds | — | — | 
                                                -64,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Net cash provided by (used in) financing activities | — | — | 
                                                -148,589,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -50,600,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Net increase (decrease) in cash and cash equivalents | — | — | 
                                                85,711,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                216,806,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Cash and cash equivalents | — | 
                                                1,269,604,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                1,183,893,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                967,086,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             |