Reiko Terajima

"Assumption Chemical Reaction". A chemistry teacher at Katagiri High School and the homeroom teacher of Hori and others. He is serious, but sometimes he tends to make negative assumptions. He is hostile to Yasuda, who seems to be hitting on female students, and sometimes he completely picks a fight. He has shown a rough trick of secretly taking Yasuda's lighter when he tried to smoke and emptying its contents. His hair is burnt brown. He ranked 32nd in the popularity poll.