The Seven Legendary Riders are in trouble. The world's newest evil secret organization, Foundation X, has aided in the research on some of the most powerful technology known to man. Gaia Memories, Medals, Astro Switches... When one rogue takes that power to use for himself, their power won't be enough.
The current generation of Riders will have to team up if they want to defeat Foundation X. In the tradition of the Kamen Rider crossovers from the classic era, these four heroes will team up to take down this new powerful enemy.