Shiga Kasumi

A student in the protagonist's class. She is good friends with Sumire and is often seen with her. She is also fond of the protagonist and talks to him about a lot of things.

She used to work at a brothel mediated by the student association in order to earn money. The protagonist admonished her and she responded with, "well, will you be my partner?" and a sexual relationship began between the two.

However, she herself is quite open about her sexual activities, so the relationship doesn't become a messy affair. She is a gossipy person and is in control of more than 90% of the rumors in the school.