The young man loses all his memory doesn't known his parents. After 10 years later, he worked the photographer living his adoptive grandfather and sister. But there is a world in danger. Tsukasa Kayoda chose our Hero as new Decade to traveled another dimension to save them. He is a Saviour or Destroyer?

An interdimensional deity known as the God of Desire summons many people are to participate in a series of games where they transform into masked warriors known as Kamen Riders, to fight against the monsters known as the Jyamato. Who will either become allies or enemies?

The world is a cruel and unforgiving place. That couldn't have been more true for a guy who crossed over from a world that knew him as a Destroyer. When he wanders and basks in his new surroundings, he finds that, this world needs a savior, but doesn't think he's the one they want.