Career
Koike starred in Kunitoshi Manda"s film The Kiss. She appeared in Kiyoshi Kurosawa"s 2012 television drama Penance. Koike co-starred in Junji Sakamoto"s A Chorus of Angels with Sayuri Yoshinaga.
She also co-starred in Masanori Tominaga"s Vengeance Can Wait with Takayuki Yamada.
She was once nominated for Best Supporting Actress at Japan Academy Prize, for her outstanding performance in the film Rebirth.