Kosaku shows new girl Ringo around the school and introduces her to childhood friend Minori Nakazawa, best friend Kei Kamatori, pet wallaby Wakadana and large breasted classmate Kocho Yoshida. During a welcome party Ringo seems oddly jealous of how close Minori is to Kosaku, at least until an unfortunate laundry room encounter turns into a "best panties" competition.