Coin-based homunculi known as the Greeed have awoken from an 800-year slumber! The only hope of stopping them in their pursuit of human desires is a rogue Greeed named Ankh, reduced to the form of a disembodied arm, and the wandering hermit Eiji Hino.

Presented with a belt and three Core Medals, Eiji steps forward as the champion of human desire - Kamen Rider OOO!