성별 : 여성
생일 : 정보신청
키/몸무게 : 정보신청

Kouichi's aunt from Ritsuko's side 
 and class 3-3 deputy homeroom teacher. She gives her nephew advice on how to make it through Yomiyama through a series of "rules". One of them, is to separate the private life from school life, thus Kouichi addresses her as Reiko at home, and Ms. Mikami at school.