Rascal-sensei is the teacher of the Banana Class at Urara School, instructing students Chacha, Riiya, Shiine, Yakko, and Orin. He possesses waist-length dark black hair, with bangs covering the right side of his face and a separate medium-length strand hanging on the left, which is occasionally tied with a yellow bow. His eyes are black, and he is consistently depicted carrying whips.

His attire varies between media. In the manga, he wears a dark long-sleeved shirt, dark pants, dark shoes, and a long cape. In the anime, his outfit consists of a short-sleeved purple shirt, black pants, and dark shoes.

His personality is enthusiastic and strict, often brandishing his whips, which intimidates his students into believing he is angry. Beneath this stern exterior, he is kind, caring, and genuinely proud of his students, demonstrating dedication by fighting for their lives when necessary. He is emotional and deeply concerned for their well-being, though not always nice.

He shares a long-standing personal rivalry with Teacher Mayachon that has existed since their birth. After Mayachon accused him of being excessively nice to his students, he promised that every student in his Banana Class would pass their final exam.

The manga reveals that he is married to Mayachon and they have a son named Amedeo, details absent from the anime.

In the anime narrative, he was once placed under the mind control of the antagonist Daimaō and later freed through purification by the Magical Princess. He was also identified as one of the eight Holy Warriors of Love, Courage, and Hope. Alongside Chacha, Riiya, Shiine, Orin, Yakko, Marin, Dorothy, and Seravy, he stormed Daimaō's castle and contributed to defeating him.