Several days after a world-spanning battle against the invading Link Joker, peace has returned. Then Aichi, the hero who saved everyone, vanishes without a trace. Worse, nobody remembers him. Nobody except Kai, who carries the weight of their friendship alone, armed only with a deck of Royal Paladins and a vision of Blaster Blade. Kai refuses to let Aichi fade into oblivion. By dueling Aichi's old companions, he helps them recall their friend, and they join his search. His hunt also pulls him into conflict with the Quatre Knights, four world-class card fighters who wield mysterious powers and urge him to give up. Their goal and their tie to Aichi remain unclear. With a new power called Legion in hand, Kai fights to bring his friend back.