When Iori Kitahara heads off to college, he decides to live at his uncle's dive shop in Izu. Iori is looking forward to experiencing college life, but ends up running into a group of tough guys playing strip rock-paper-scissors. Iori gets dragged into the diving club's crazy shenanigans and ends up spending his first day in college wearing nothing but a pair of underwear.

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 Kohei don wetsuits and head to the sea! Although Iori used to be afraid of the water, he starts becoming more interested. But diving equipment is expensive! Tokita and Kotobuki decide to hold a men's beauty pageant for the Izu Spring Festival in May. The guys want to avoid being paraded around on stage, so they try to get Chisa to participate in a women's beauty pageant.