The world, these are Japan's heroes!!
The course of history is accidentally changed when Ankh leaves behind a Medal in the past after Kamen Rider OOO helps Den-O and New Den-O chase a Mole Imagin all the way back to November 11, 1971. When they return to the present time on April 1, 2011, they discover that Shocker succeeded in conquering the world and now Kamen Rider 1 and 2 are Shocker's top agents. In order to defeat Shocker, Kamen Rider OOO and the Den-Liner gang must travel back in time to gather other Kamen Riders to defeat Shocker and restore the proper timeline.