Koike started a junior idol career with the DVD Big Brother at age 10, when she was in 4th grade. Koike Rina played Sailor Luna in the 2004 live-action version of Sailor Moon, Pretty Guardian Sailor Moon. She also played the role of Shizuka on the 2008 Kamen Rider Series, Kamen Rider Kiva. In early 2011 she starred in the short TV drama Onegai Kanaete Versailles, alongside visual kei metal band Versailles. After graduating from Asia University in 2016, Koike took a two-year break from the entertainment industry to spend time studying English in New Zealand and Australia.
Kamen Rider Backwards-Kiva: Queen of the Demonic Castle
(Shizuka Nomura)
Kamen Rider Kiva: King of the Infernal Castle
(Shizuka Nomura)
Girl's Blood
(Mayu)
Tales of Terror: Final Night 2
The Serialist
Grand Guignol
Kaidan Shin Mimibukuro: Dai Go Ya
Ultraman Ginga S the Movie: Showdown! The 10 Ultra Warriors!
(Sakuya)
Hobonichi no Kaidan: Vol 1
Yunagi City, Sakura Country
Tales of Terror: Final Night 1
Happy Landing
(Aiko Machida)
Yakuza Ladies Neo
Kamen Rider Den-O & Kiva: Climax Deka
(Shizuka Nomura)
Ultra Fight Victory
(Sakuya)
Punch the Blue Sky
Innocent Lilies: The End And The Beginning
(Rina Kinugasa)
Nile Perch Girls' Association
(Mahiro Takasugi)
Hatsukoi Geinin
(Eri Yamaguchi)
Pretty Guardian Sailor Moon
(Luna Tsukino / Sailor Luna)
Mother at Fourteen
(Nagasaki Sayaka)
Sailor Zombie
(Arina)
Kamen Rider Backwards-Kiva: Queen of the Demonic Castle
(Shizuka Nomura)
Great Selection Taxi
(Yoko Kuroda)
Ultraman Ginga S
(Sakuya)
Nikenme Dou Suru? ~Tsumami no Hanashi~
Kamen Rider
(Shizuka Nomura)
ISHIKO and HANEO: You're Suing Me?
三代目明智小五郎〜今日も明智が殺される〜
(小林 めぐみ)
Gourmet Detective Goro Akechi
(Hina)
Masked Rider Kiva
(野村静香)