Koharu is one of Yume's bestfriends. She has been with Yume every since they were kids. The two audition to get into the academy, both making it, as their idol adventure begins with each other. Koharu has a light but soft voice. She is a quiet, and shy character. But has a very soft voice. She is smart, and loves S4, and idols just in general. She is a cute type of idol, but you don't hear her sing until later on in the series.