Eiji Hino is a drifter without a home and a tragic past. When metallic beings known as the Greeed awaken from their 800-year slumber to attack humans and feed on their desires, the disembodied arm of the Greeed named Ankh grants Eiji a belt and three Medals to combat the other Greeed as Kamen Rider OOO. The enigmatic Kougami Foundation approaches Eiji, offering assistance in his battle against the Greeed, though their true intentions remain unclear. As Eiji confronts the Greeed and their Yummy monsters, uncovering more about the Greeed and Ankh, he begins to discover a purpose beyond his own journey.
