Futaba decides to draw an erotic manga for Yuudai, roping in Shinya to help her learn to draw underwear on her figures. The school practices a fire drill, with Yabe's imagination getting the better of him. During a sports event, Soujiro ends up losing his clothes in preparation for a three-legged race with Hitoha, landing him in an awkward predicament. Yuudai invents a new move to unhook girl's bras, which leads to various misunderstandings while trying to find someone who actually wears a bra...