Kamen Rider OOO is a Japanese tokusatsu television series and the twelfth entry in the Heisei era of the long-running Kamen Rider franchise. The story follows Eiji Hino as he transforms into Kamen Rider OOO to battle monsters known as Greeed, using a variety of Core Medals to access different powers and forms. The series is known for its unique transformation gimmicks and engaging story arcs.