Diving involves a lot of equipment in good order, which means it’s quite a costly activity for a college club to be involved in; far costlier than, say, the tiddly winks club or the pogo stick club. Iori and Kouhei are informed of this in a matter-of-fact way, meaning they will have to help contribute to club funds.
They already have a way for them to contribute right away: by participating in the Izu Spring Festival’s Inter-Club Men’s Beauty Pageant. But before that, Ryuu takes Iori out for his very first scuba-diving lesson. Before he departs, he gets words from encouragement from Chisa.
Chisa is clearly excited that her old friend is about to experience something she’s already familiar with—and which she loves. Things start out a bit rough, as Iori isn’t used to the kind of breathing one does in scuba gear, and when his mask floods he panics.
But once everything is readjusted, he remembers what Chisa showed him at the aquarium, and it’s like stepping through the doorway into a new world. You can see the switch flip in Iori’s head from panic to nirvana, and the look of joy and wonder on his face is plain to see—and something that delights Chisa. “Good, he gets it now,” she seems to be thinking.
The wonder and joy lead to excessive celebration, which is nothing new to Iori and Kouhei, but what is new is the manner in which Iori finds himself waking up: beside a buxom half-naked woman a couple years her senior. This is how he meets third-year student and fellow diving club member Hamaoka Azusa.
Azusa is the kind of girl who doesn’t mind sleeping in the same room with a bunch of guys, but she’s also a good cook, and teaches Iori, Kouhei and Chisa how to make okonomiyaki to raise more funds for the club at the festival. The festival where, in exchange for not having to compete in the boy’s pageant, the boys must convince Chisa to compete in the girls’ pageant.
The lads, likely still hungover, decide the best way to convince Chisa is to liquor her up so she’ll be more open to the pageant. However, each time they try to slip her a spiked drink, she either already has one, politely declines, it’s taken by Azusa, or one or both of them have to take the drink. Before long, they’re drunk as skunks.
Azusa also reveals she knows what they’re up to—to the heretofore unaware but now horrified Chisa—and forces them to confess their true goal. They ask Chisa to enter the pageant; she refuses; and they reveal that they’re trying to get her to enter so they don’t have to.
That night, the lads play naked rock-paper-scissors, which Azusa joins in but doesn’t have to shed a single article of clothing as she whoops everyone. She gets Chisa to admit that it’s not that she doesn’t want to enter, but more that she doesn’t want to bear the embarrassment of the pageant all alone. Azusa also points out that the only reason they asked her at all is because they were supremely confident all she’d have to do is enter and her victory would be assured.
So Chisa agrees to enter…but only if Iori and Kouhei enter too. Thus the embarrassment is shared, if one loses one of the other two could still win, and if all three win, the club funds are tripled, so everyone wins. When the means with which to enter a new world are so expensive, sometimes you just gotta shake what your mama gave ya…proverbially!