OOO, pronounced similarly to "O's", premiered in late 2010 following the finale of W. Eiji Hino is unwillingly drafted by a being known as Ankh to be his guard in the fight amongst the Greeed, monsters whose powers stem from mystical coins known as Core Medals. When they awoke, several of their Core Medals were missing; Ankh having lost most and thus stole some from his kin. As the Greeed hunt down their Core Medals, they use Cell Medals to create monsters called Yummy to produce more Cell Medals to sustain their incomplete bodies. However, Ankh uses Eiji Hino and gives him the OOO Driver to allow Eiji to transform into Kamen Rider OOO to get the Medals for him. However, a third party is also after the Medals for mysterious reasons in the form of the mysterious Kougami Foundation.