Swimming school summer camp. Lessons should be fun under the clear blue sky... but students Shota and Chibisuke end up ignoring swimming and chasing the beautiful buttocks of their beautiful coach, Ema. Ema loses her patience and scolds the two, but later gets a hot counterattack from Shota and the others. One day during a lesson, Chibisuke suddenly drowns and Ema goes to rescue him. After some accusation, the two of them play with her, and they end up having sex. But that night, Ema's crotch is throbbing and she takes action to soothe her hot body. On the last day before going home, what is the commotion that begins with a wish...?