Gensou no Altemis [JP]

The game takes place in Ikoma Aku Torres Actress School where different girls go to grow their perfomance abilities, and one night when a performing is taking place the owner of the school jump off a roof to the death. The police think that is just a suicide, but the motive is still a mystery, so the people on charge of the school decide to hire a private detective (Kiyouiti Kusakabe) to make an investigation. So when they hire him they decide that he enters the school as a new instructor in the academy. That's when the game begins.