
Acting
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.

Girls Remix in Halloween Party
as Shizuka Nomura / Kamen Rider Kiva-la

Grand Guignol

Hobonichi no Kaidan: Vol 1

Ultra Fight Victory
as Sakuya

Ultraman Ginga S the Movie: Showdown! The 10 Ultra Warriors!
as Sakuya

Innocent Lilies: The End And The Beginning
as Rina Kinugasa

Happy Landing
as Aiko Machida

Girl's Blood
as Mayu

The Serialist

Yakuza Ladies Neo

DREAM STAGE
as まなの母 · 1 ep.

ISHIKO and HANEO: You're Suing Me?
1 ep.

Nile Perch Girls' Association
as Mahiro Takasugi · 8 ep.

Gourmet Detective Goro Akechi
as Hina · 3 ep.

Nikenme Dou Suru? ~Tsumami no Hanashi~
1 ep.

Hatsukoi Geinin
as Eri Yamaguchi · 8 ep.

Ultraman Ginga S
as Sakuya · 16 ep.

Great Selection Taxi
as Yoko Kuroda · 1 ep.

River's Edge Investigative Agency Okawabata
12 ep.

Sailor Zombie
as Arina · 12 ep.