"Third Night" Izumi Hinagawa, the ace of the swimming club, is an object of admiration for her juniors. Aki Sakuragi is one of them. After practice, Izumi finds a pair of white panties in a bag someone has left behind and confirms that they belong to Aki. Izumi gently spreads the panties open and presses them to her nose... "Fourth Night" When Aoi woke up, she found herself in a dimly lit room reinforced with concrete on all sides. Then the door was unlocked, and men took turns assaulting her. "How long have I been here...?"