Kido

is a teacher at Saint Ishiyama Academy. He teaches student life and is a strict enforcer of the academy's policies.

Saint Saint X'mas Arc
During break in the staff room, Kido talks to Saotome about the high school's annual Saint Saint X'mas competition, stating how the number of couples that emerge from the event is increasing every year. A fellow teacher brings up how the students of Ishiyama will likely not care for the special occasion due to the second reconstruction of their original high school; on this matter, Kido states that he is also aware of the news.

On Christmas Eve, Kido helps out with the annual competition by participating as a judge for one of the matches. He watches the two couples act out different scenarios during the match; among the four judges, he gives out the lowest score for the Nishizawa and Yonehara pair in their first scenario, noting how the former's performance, despite its moderate quality, is not genuine. However, he gives out top scores for Hidetora Tōjō and Shizuka Nanami due to the latter's own acting. During their performances, he smiles pleasantly at them, unlike the other three who all burst into tears.