She is Bossun, Hime, and Switch's classmate in the Sket Dan franchise.
Not much is known about her past. Kumi is a minor character.
In episode 14, Kumi wishes Chuumi, the chemistry teacher, to stop teaching. During Bossun's flashback to rally the class to support Uchida, Kumi states that she voted for Uchida. In the contest's results, she is chosen to be Ms. Sexy.