The year is 2021, ten years after Eiji first became Kamen Rider OOO. The ancient OOO has come back to life and brought with him the Greeed, Uva, Kazari, Mezool and Gamel to exterminate humanity and take over the world.
Eiji's friends all form a resistance to fight the ancient OOO, but Eiji himself disappears after clashing with the ancient OOO. Ankh is then mysteriously revived and joins up with the resistance to figure out what happened to Eiji and stop the ancient OOO. What will be the fate of Eiji and Ankh? Now, the battle of the kings for the survival of mankind begins...!
