After a cutthroat battle with Kohei Imamura, a handsome otaku from school, Iori ends up joining the Peek-a-Boo diving club. Iori arrives home worn out from the day, but perks up when he hears about a party with a women's college. However, his cousin Nanaka won't allow him to stay out three nights in a row, so Iori tries to show her he's an independent man to get her to let him go.

Iori and the others dream about going diving at a beautiful location after seeing an article on Miyakojima in a magazine. However, Tokita and Kotobuki decide the club is going to join a tennis doubles match! They explain that they're joining the match to get everyone to build trust with their diving buddy, but the real reason is to get back at the tennis club and take away their prize money!