Subclassifications Of Assets, Liabilities And Equities [Abstract]
| Concept | As at 2024-03-31 | As at 2024-03-31 | As at 2024-03-31 | As at 2023-03-31 | As at 2022-03-31 | 
|---|---|---|---|---|---|
| Subclassifications of assets, liabilities and equities [abstract] | |||||
| Property, plant and equipment [abstract] | |||||
| Property, plant and equipment | 
                                                696,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | 
                                                -
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | 
                                                696,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | 
                                                696,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | 
| Intangible assets and goodwill [abstract] | |||||
| Intangible assets other than goodwill [abstract] | |||||
| Intangible assets other than goodwill | 
                                                5,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | 
                                                -
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | 
                                                5,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | 
                                                5,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | 
| Trade and other current receivables [abstract] | |||||
| Current trade receivables | 
                                                -
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | 
                                                -
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | 
                                                -
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | 
                                                -
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | 
| Other current receivables | 
                                                373,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | 
                                                233,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | 
                                                140,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | 
                                                148,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | 
| Categories of non-current financial assets [abstract] | |||||
| Non-current financial assets | 
                                                15,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | 
                                                -
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | 
                                                15,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | 
                                                15,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | 
| Cash and cash equivalents [abstract] | |||||
| Cash and cash equivalents | 
                                                736,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | 
                                                -
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | 
                                                736,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | 
                                                1 269
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | 
                                                1 791
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | 
| Non-current assets or disposal groups classified as held for sale or as held for distribution to owners [abstract] | |||||
| Non-current assets or disposal groups classified as held for sale | 
                                                -
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | 
                                                -
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | 
                                                -
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | 
                                                -
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | 
| Miscellaneous current assets [abstract] | |||||
| Other current assets | 
                                                0
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | 
                                                -
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | 
                                                0
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | 
                                                0
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | 
| Classes of other provisions [abstract] | |||||
| Other provisions [abstract] | |||||
| Other non-current provisions | — | — | 
                                                217,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | 
                                                126,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | 
| Borrowings [abstract] | |||||
| Non-current portion of non-current borrowings | — | — | 
                                                0
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | 
                                                0
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | 
| Non-current portion of non-current borrowings, by type [abstract] | |||||
| Trade and other current payables [abstract] | |||||
| Current trade payables | — | — | 
                                                60,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | 
                                                93,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | 
| Current accruals and current deferred income including current contract liabilities [abstract] | |||||
| Current deferred income including current contract liabilities [abstract] | |||||
| Current contract liabilities [abstract] | |||||
| Current advances received, representing current contract liabilities for performance obligations satisfied at point in time | 
                                                -
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | 
                                                -
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | 
                                                -
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | 
                                                -
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | 
| Miscellaneous current liabilities [abstract] | |||||
| Other current liabilities | — | — | 
                                                42,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | 
                                                60,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | 
| Issued capital [abstract] | |||||
| Issued capital | — | — | 
                                                2 330
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | 
                                                4 584
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | 
| Retained earnings [abstract] | |||||
| Retained earnings, profit (loss) for reporting period | — | — | 
                                                580,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | 
                                                643,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | 
| Retained earnings, excluding profit (loss) for reporting period | — | — | 
                                                2 023
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | 
                                                413,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | 
| Net assets (liabilities) [abstract] | |||||
| Assets | 
                                                1 825
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | 
                                                233,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | 
                                                1 592
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | 
                                                2 132
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | 
| Net current assets (liabilities) [abstract] | |||||
| Current assets | 
                                                1 109
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | 
                                                233,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | 
                                                876,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | 
                                                1 416
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | 
| Current liabilities | — | — | 
                                                103,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | 
                                                154,000
                                                
                                                    
                                                        EUR
                                                    
                                                
                                             | — | 
| Assets less current liabilities [abstract] |