The "Desire Grand Prix" is a game to protect the peace of the city from the threat of the mysterious enemy "Jyamato", whose origin and purpose are unknown. Each participant transforms into a Kamen Rider and competes to win the game by defeating enemies and saving people. The winner of the Desire Grand Prix will be rewarded with "the right to bring an ideal world to life" as a prize. In other words, only the true heroes who win the competition will be able to realize the world they have wished for.

The Quartzers, calling themselves the Wardens of Time, appear after Sougo Tokiwa has collected all of the Heisei Era Ride Watches. A grand conspiracy behind the birth of the King of Time becomes ever clearer...