Kotesashi Ritsuko

She is the homeroom teacher of Yuuki's class. She wears thin rimless glasses and is strict and intelligent about education.

She has a medium build and a medium height. She has large breasts, which causes her colleagues to look at her erotically, which is a source of concern. Her only daughter, Riri, attends the school where he works and is constantly fighting with Yuuki and his friends.

She lives at home, so her grandparents take care of her during the day.