Penguin-sensei is a penguin character serving as a teacher and manager at Pretty Top, the institution training Prism Stars. He sports light green plumage and aqua-green hair that often covers his orange eyes. In his primary role instructing Coach Mascots and Pair Charms, he exhibits eccentric behavior, frequently attempting to appear on camera or television broadcasts. He is often perched on the shoulders of his colleague Yamada Yamao and endures regular scratches from the Pair Charm Vivvy. Within *Pretty Rhythm: Aurora Dream*, he is recognized as Pretty Top's most capable instructor and was the first to provide lessons to protagonists Aira Harune and Rizumu Amamiya. He reacts strongly to being called a stuffed animal, prompting Aira to retract such statements. During *Dear My Future*, he authorizes Mia Ageha's enrollment at Pretty Top and demonstrates unconventional teaching methods, including pelting animal coaches with tubs. A significant backstory revealed in *Pretty Rhythm: Rainbow Live* shows he was formerly partnered with Prism Star June Amou before his teaching career. This partnership ended when he allowed June to continue performing during a new moon event, nearly causing a Prism Show disaster. As punishment for this lapse, Peacock, a higher authority in the Prism World, banished him to Mascot Hell. His confinement there persists into the *Pripara* series, where he appears in Episode 19 and the associated movie. In the film *Pretty Rhythm All Star Selection: Prism Show Best Ten*, Penguin-sensei acts as a navigational figure alongside mascots Momo and Akai Meganee. They introduce and contextualize the "top ten" Prism Shows from the franchise's history, framing archival footage with new transitional scenes set in the Prism World. This role positions him as a guide to the series' legacy. His involvement across media remains consistent with his core traits as a dedicated yet peculiar mentor entangled in the mystical governance of the Prism World.