Koharu Kusumi is a J-pop singer.

She joined Morning Musume as the only seventh generation member and as the youngest soloist to debut in Hello! Project, being only twelve years old when she joined. Before Koharu joined Morning Musume, she was the captain of her school's volleyball team.

Koharu has been a member of the Hello! Project kickball team Metro Rabbits H.P. since its formation in the beginning of 2006 and since April 7, 2006, she has been the voice actress for Kirari Tsukishima, the main character in the anime Kirarin Revolution.

In early 2007, Kusumi was chosen to be a member of Morning Musume Tanjō 10 Nen Kinentai, a unit created to celebrate Morning Musume's 10th anniversary as a group. Morning Musume Tanjō 10 Nen Kinentai also consists of Kaori Iida, Natsumi Abe, Maki Goto and Risa Niigaki. Their first single, Bokura ga Ikiru My Asia was released on January 24, 2007.

Apart from her activities in aforementioned units, Koharu is also a member of Kira☆Pika with °C-ute's Mai Hagiwara and Milky Way with Hello Project Eggs members Kikkawa Yuu (who also auditioned for Morning Musume back in 2006) and Kitahara Sayaka. Both units were formed for the Kirarin Revolution anime.

* Name: 久住 小春 (Kusumi Koharu)
* Birth date: July 15, 1992
* Birthplace: Nagaoka, Niigata Prefecture, Japan
* Blood Type: A
* Height: 162cm (5'3.8")