Kusugi, formally addressed as Kusunoki-sensei, is Miyo Sasaki's teacher. He is present in the classroom when a classmate intercepts Miyo's love confession intended for Kento Hinode and reads the letter aloud publicly. This act causes significant embarrassment for Miyo and Hinode and directly leads to Miyo's emotional decision to remain permanently in her transformed cat state. Kusugi's role is confined solely to the main feature film, with no documented appearances or expanded background in supplementary media like OVAs, spin-offs, or manga adaptations.