Based on the game by Biscotti.

Shun is the only male teacher at Kyoukasen Girls' School, a well-known high class school also known as the "Water School" since it is situated in a forest with a lake on the school grounds. It is a place of recovery for those who have been mentally wounded. He meets girls who have shut themselves off from the world, those who don't have confidence in themselves, those who are still traumatised by their past. He decides to help them move forward with their lives.