Koharu Kusumi is a Japanese singer, actress, model, and voice actress born on July 15, 1992, in Niigata Prefecture, Japan. Her career as a voice actress began and is primarily defined by her role as the main character in the anime series Kirarin Revolution.

In 2005, Kusumi became the sole seventh-generation member of the popular Japanese idol group Morning Musume, part of the Hello! Project. Shortly thereafter, she expanded her career into voice acting. In April 2006, she was cast as the voice of Kirari Tsukishima, the protagonist of the anime Kirarin Revolution, a role she held until the series concluded in 2009. This casting made her one of the early examples of the idol voice actor crossover trend that gained popularity in the late 2000s. Her work on the series extended beyond voice acting; she also performed the character's songs, releasing solo music under the name Kirari Tsukishima starring Koharu Kusumi (Morning Musume). Notable singles released under this name include Koi Kana and Balalaika. Additionally, she was part of musical units formed for the anime, such as Kira Pika and MilkyWay.

Kusumi's portrayal of Kirari Tsukishima crossed over from animation into live appearances. She appeared as the character on the children's television program Oha Suta and in the live-action mini-drama Kira Revo+. Her work on Kirarin Revolution remains her most significant achievement in voice acting, and she is recognized for her role as a pioneering figure in the integration of pop idol and voice acting careers. No information is available about other major anime voice roles or recurring collaborations with specific directors or studios beyond the Kirarin Revolution franchise.