Iori and Kohei attend class in their underwear like normal, but everyone glares at them with a bloodthirsty look in their eyes! It's because they heard that Iori and Chisa are dating! Sensing their lives are in danger, Iori and Kohei offer to setup a mixer. They ask Azusa to introduce her friends, but she brings Aina Yoshiwara, the "Cakey" girl from the Izu Spring Festival!

Inori and Kohei get through their exams by cheating. Meanwhile, PaB throws a welcome party for Aina, their new member. Aina was looking forward to getting a new start to college life, but discovers that no one in the club is normal! Nevertheless, the club members are serious about diving and have the new members learn basic hand signals and dive in pairs. However, Iori gets paired up with Chisa.

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!

The members of the diving team start working part-time jobs to pay for their trip to Okinawa. However, Iori and Kohei end up spending all their earnings on drinking. Meanwhile, Kotobuki is working hard as a bartender, and his boss lets Iori and Kohei try it out too. However, these two idiots don't know how to make cocktails, and end up creating some dangerous new drinks!

Iori tries to setup another mixer for his friends, and wants to ask Chisa to introduce her friends so they can all play truth or dare. Nanaka and Azusa also get involved, and they all begin a vicious game of attack and defense! However, Iori doesn't have enough money for their trip. Iori and the gang head to a diving shop to buy diving gear, but find out there's still a lot they don't know.