This game ― The winner in the end is me.

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.