Sachiko Tanaka

A truant student of Junichirou's who doesn't go to school so she can work as a mangaka under the penname "Kisaki Tenjouin".

She's rather apathetic and laidback and seems to only really care about her fans. However, she does care about her other classmates at times, although her and the student council president, Makina Momozono, don't seem to be on very good terms.

Junichirou calls her "Kisaki-sensei" and is a fan of her manga "Shuumatsu Gakuen", even calling it a masterpiece. Her previous manga was called "Hanauta" and was supposedly very popular until the magazine ceased publication. As such, the last chapter was never published.

[Spoiler] After her character arc, Junichirou manages to bring her back to school where she works on her manga most of the time. [/Spoiler]