Sylvan Disappearance is a mystery visual novel with an epistolary component. In the course of the story, you follow Mirabelle's life in a seaside city, and read the correspondence she receives from her friends Martin and Célia.

Mirabelle and Célia have always loved inventing stories, and acting on stage too. They used to entertain their friends by running story nights for them, in the woods near their village. Not anymore, though. Three months have past since the incident which shattered their friendship, and Mirabelle has begun a new life far away, in a bustling city by the sea. One day, Mirabelle receives a letter from Martin, another friend of hers: This is none of my concern, surely, but I fear I must ask... Has Célia written to you yet? If I may hazard a guess —she has not at all, has she? I do not believe that she has spent a very pleasant summer, but I would like to believe that very soon, life will turn out all the better for her. If you ever find the time, do not hesitate to write to her. Could this mark the beginning of a renewed friendship? Perhaps. But not all secrets can be told truthfully, even to one's closest friend.