Teenager Kit Taylor discovers a mysterious deck of Advent Cards that grant him the power to transform into an ancient armored warrior called a Kamen Rider. He joins Kamen Rider comrade Wing Knight to battle the renegade warlord General Xaviax and his army in both the real world and an alternate reality called Ventara, or Mirror World.
On the other side of the mirror exists the parallel dimension of Ventara, where warriors known as the Kamen Riders fight againist the evil warlord Xaviax with their Advent Decks. In a war that resulted in all the Riders being wiped out, its lone survivor Len follows Xaviax to Earth, where the general tricks ordinary citizens into becoming new Kamen Riders to carry out his evil plans. While investigating the mysterious disappearance of his missing father, Kit Taylor finds an Adveck Deck and becomes Kamen Rider Dragon Knight, joining forces with Len, Kamen Rider Wing Knight to defeat the ten corrupt yet midguided Riders sent to attack them by Xaviax. They fight not only to save Earth from being destroyed by Xaviax, but also to find Kit's missing father and take back the home they hold dear.