In the middle of the forest, there is a beautiful lake and a spacious western-style building where 12 people lived. They had all lost their memories and woke up to find themselves in this place. With many books in the library, instruments in the music room and absolutely no troubles, it is like a paradise for the residents. Even if they wanted to leave, they can’t because it is surrounded by a sea of trees and darkness. No one has been known to have successfully left. Then, one of the boys disappeared and Kai gradually remembers his past. He wants to find out why he is here, but is warned against doing so. What would happen if he regains his memories?