Kyōki Saiko is a supporting character who appears as a student at Asunaro High School and serves as the general affairs officer of the student council. He is the older brother of Fuyusaku Nishiko, a classmate of Morihito Otogi. Saiko deliberately cultivates an unnerving persona, often pretending to be insane in order to frighten those around him. His most notable habit is licking blades, a behavior that frequently results in him cutting his own tongue. Despite this bizarre exterior, Saiko is actually a self-conscious individual who had difficulty making friends before joining the student council. He was recruited by the student council president, Tenryu Seimiya, and has since developed strong affection and respect for his fellow council members and his friends. His motivations appear to center on maintaining his intimidating facade, though his underlying desire for genuine connection is evident in his loyalty to the people who accept him. Within the story, Saiko occupies a primarily comedic and supporting role, contributing to the school setting and the student council dynamic. He does not possess any supernatural abilities; his distinguishing traits are his theatrical behavior and his peculiar knife‑licking compulsion. Over the course of the narrative, he remains a stable presence, finding a sense of belonging in the council and showing glimpses of a playful, if eccentric, personality beneath his act.