We already had some impression of Chizuru's swimming skills in episode 2 - but nonetheless, their school's swimming club nominated the ""Three Amigos"" (Chika, Natsuki and Chizuru) as their relay team for the ""18. Regional Swimming Competition"". Which means that each member has to swim at least 25 meters. But all is not lost, as they happen to know the best swimming coach in the world: Tina Foster! So they're going to swim like fish...