Sakie Satou

A succubus who works as a math teacher. She constantly has to take precautions to avoid inadvertently seducing her male students, by making herself look dull. She wears a track suit and avoids make up, but if a person touches her they become aroused, which causes her to avoid contact. When she accidentally touches Tetsuo, he pretends not to be affected as to not make her feel uncomfortable, which ends up making her form a crush on Tetsuo.

(Source: Wikipedia)