There is a fitness gym that has a reputation for being able to get the body of any man who joins, no matter how slack he is... Reiko, an instructor at this seemingly ordinary gym, uses a secret member management method to have her members work stoically on body transformation. Her method is to use the bait of beautiful buttocks to make the members wear chastity belts, and only those who achieve results are given the "reward" of ejaculation. Every day, the members dream of ejaculating and continue to train at the gym...