Koharu Kusumi joined in 2005 as the only seventh generation member of Morning Musume.

Kusumi 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 (きらりん☆レボリューション, Kirarin Revolution?).

In early 2007, Kusumi was chosen to be a member of Morning Musume Tanjō 10 Nen Kinentai (モーニング娘。誕生10年記念隊, 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 (僕らが生きるMy Asia, Bokura ga Ikiru My Asia?), was released on January 24, 2007.

Apart from her activities in aforementioned units, Kusumi 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.

she looks so cute: