Several days after the mortal battle against Link Joker which embroils the whole world, the world has returned to peace.
But Kai Toshiki faces a surprising situation. Sendou Aichi, who saved the world from the invasion of Link Joker, has suddenly disappeared. In addition, everyone’s memory of Aichi is lost… Almost all hints have been lost, and Kai starts to search Aichi with Blaster Blade and the deck of Royal Paladin, the only existing hint and the proof of their bonds.
Kai is approached by fighters who call themselves Quatre Knights. The four Gaillard, Neve, Ratie and Sera are fighters who control mysterious powers in vanguard fights, and urge Kai to give up searching for Aichi. What is their goal, though? And what is their relationship with Aichi?
Kai, with the new power Legion in his hand, fights to find Aichi.