Penguin Teacher is a penguin and instructor at Pretty Top, where he's considered the school's best teacher. He was the first to mentor both Aira and Rizumu, though he's always struck the trio as pretty awkward. He has a notoriously short fuse whenever Aira mistakenly calls him a stuffed animal—she usually catches herself mid-sentence once she sees him getting angry.
One of his stranger quirks is his constant need to insert himself into cameras and TV appearances, which plays into his generally odd behavior throughout the series. He typically perches on Yamada's shoulders during lessons.
Pretty Rhythm: Rainbow Live reveals that Penguin Teacher and June were actually partners at one point before the events of the main series. He eventually left her to take on his teaching position at Pretty Top. By the series finale, his antics finally catch up with him—he ends up falling into Mascot Hell as Peacock's punishment.
Content compiled by AnimeList.moe from publicly available sources.
