Cardfight!! Vanguard: Legion Mate-hen

After the battle against Link Joker, Kai expects Card Capital and the people around him to have returned to normal. Instead, he discovers something impossible: everyone has forgotten Aichi Sendou, as if his closest friend never existed at all. Kai alone remembers him.

A vision of Blaster Blade and the sudden appearance of Aichi's Royal Paladin deck give Kai the first proof that his memories are real. By challenging Aichi's former friends, he begins restoring what they lost and gathers allies for the search. But mysterious fighters known as the Quatre Knights stand between them and Aichi, determined to keep the missing Vanguard fighter beyond their reach.