Pina Sformklan Estoh, First Princess of the Northern European kingdom Suforu, wears her crown as a symbol of her position. Her transfer to Hakureiryō Academy in Japan stems from a deep fascination with Japanese anime, especially the series "Magical Diva," a passion she openly claims as central to her identity. She expresses frustration towards Japanese youths unfamiliar with domestic anime culture, contrasting this with her own extensive knowledge of otaku hobbies like cosplay and doujinshi creation. This fervent interest initially isolates her, as she finds no peers sharing her passions except the academy's principal, Kaede Tenjōji, who also enjoys anime and eroge.

Pina communicates using an archaic Japanese dialect, employing terms like "onushi" for "you" and ending sentences with "ja," reflecting her foreign royal heritage. Her character exhibits playful and occasionally intrusive behavior, particularly directed at fellow student Mimina Ōsawa. She actively pursues Mimina for cosplay collaborations, convinced Mimina perfectly resembles the character Magical Kaede from "Magical Diva." Their partnership in creating a doujinshi leads to emotional moments, such as Pina crying tears of happiness upon Mimina's agreement. During cosplay photoshoots, Pina displays physical affection, including holding Mimina's hand, cuddling, and cheek-rubbing. She also demonstrates clinginess by following Mimina to locations like summer villas and clothing stores.

One notable incident occurs in a dressing room where Pina, after removing Mimina's bra, touches Mimina's breasts from behind. She discusses breast size preferences as a "fetish" and offers to massage them for perceived enlargement, citing techniques from a doujinshi borrowed from Principal Kaede. Pina later comments to Akiharu Hino that teasing Mimina is enjoyable, accompanied by giggling. Her otaku enthusiasm drives her involvement in school activities, such as recruiting Akiharu and Tomomi Saikyō to assist with her doujinshi project and later gifting Akiharu passport tickets to the "Try Aqualand" waterpark. While her role centers on facilitating events related to her interests, her relationships, particularly with Mimina, indicate a development from loneliness toward collaborative engagement through shared creative pursuits.