Sudou Mio

Mio is a second grade high school student and classmate of the protagonist. She is a class president and a serious and meddlesome person. She is Keita's close friend and Tomoka's senior at her workplace.

She hates her brother because of his perverted speech. She occasionally helps with the student council work along with Keita because she is worried about him.

She can sometimes be gentle and sometimes harsh.