Hakase is a classmate of Shōta Ōhara in elementary school, nicknamed "Professor" for his sharp mind and extensive knowledge. He exhibits a strong passion for inventing despite his youth.

Physically, he is notably short for his age and already bald, an unusual trait for a child. He consistently wears glasses, and his sleeves are depicted as perpetually too long.

He resides with his stubborn grandfather, for whom he harbors deep affection. His personality includes significant sensitivities: he suffers from extreme motion sickness triggered easily by vehicles, to the point where even seeing a picture of a bus induces nausea. He also has a fear of heights.

Within his group, he interacts with classmates Shōta Ōhara, Yoshiko Koizumi, Tsuyoshi Saigo, and Kizao Kiza, as well as the ghosts Q-taro, P-ko, O-jiro, Doronpa, and U-ko. His intellect and inventive nature contribute to various situations involving these characters across the series.