Jinba high school is a prestigious school where political and business elite children study. A small passenger ship "Silent" is a place for a student party. Hero is preparing the party in the course of his part-time job. The next morning after the party a female teacher is discovered abused and killed. The crew hurried towards the ground, but other incidents happen one by one involving girls assaults. Hero is requested to help the investigation by the teachers.

[From vndbreview]