During a joint recess with first graders, Mitsuba retrieves a RC coptor stuck in a tree belonging to Miku's little brother, Ryuuta, who is also a Gachi Rangers fan. When Hitoha shows him her merchandise, Mitsuba misunderstands the situation and comes off as a pervert. When Miku implies that Mitsuba is a 'nympho', Mitsuba gives her own definition when asked by Ryuuta, which comes back to haunt her when his classmates take it literally. Mitsuba and Futaba later find some of Hitoha's Gachi Ranger merchandise and inadvertently break them, ending up trying to steal replacements from Ryuuta. Whilst Futaba apologises to Hitoha, Mitsuba, who mistook her Gachi Ranger belt as an exercise belt, ends up getting punished after a failed attempt at pinning it on Soujirou. Later, Mitsuba gets a cold and becomes more irritating when Miku, Yuki and Miyashita come to visit. When Mitsuba's fever worsens, they and Hitoha have trouble getting a suppository medicine up to her. With Miku's help, they manage to get the medicine to her, only to later find it was intended for Sojirou's hemorrhoids.