During summer break, swim-club coach Aya takes her team to a training camp. While she is determined to reach the national championships, the adult student role-players are interested only in the enormous J-cup breasts bouncing inside her racing swimsuit. Instead of training, they spy on her changing and showering, then plot to confess their desire and sneak into her room at night. Aya discovers the scheme at the last moment and scolds them, but they ignore her protests, overpower her, and take turns with her...