Summer swimming camp at the local swim school. Students are supposed to be cheerfully attending lessons under the clear blue sky. However, Shota and Chibisuke are more infatuated with their beautiful coach, Ema, than focused on swimming, causing them to neglect their training. Ema finally loses her patience and scolds the two harshly. But her half-hearted punishment backfires—later, she finds herself on the receiving end of an intense counterattack from Shota and his friend. One day during practice, Chibisuke suddenly sinks underwater, prompting Ema to rush over in rescue. At that moment, she falls victim to Shota's mischievous advances, which escalate into full-on sex. That night, Ema's groin aches with desire as she soothes her burning body. On the final day, just before heading home, an unexpected turn of events unfolds—sparked by a simple wish.