Cardfight!! Vanguard: Legion Mate-hen

Synopsis

After the end of the Link Joker incident and having an ominous dream, Kai goes to Card Capital. However, when he asks Shin and Emi about Aichi, neither of them remember Aichi or know who he is. Furthermore, when Kai goes to Miyaji Academy to ask Misaki if she remembers Aichi (to no avail), he also learns that the Miyaji Cardfight Club is gone, or rather it never existed at all. It is as if Aichi's existence has been completely erased. Kai goes to the room where the club would always meet and laments about Aichi but then remembers the Blaster Blade card. Suddenly, a Royal Paladin deck containing a new version of Blaster Blade appears before Kai. As he exits Miyaji Academy, Naoki stops him. As if reverting to his former self prior to meeting Aichi and playing Vanguard, Naoki asks about Kai's deck, which he responds by saying it is a Vanguard deck. Naoki shows slight signs of recalling everything, so Kai decides to play against him to jog his memory.

Kai and Naoki return to Card Capital where Misaki gives Naoki a Narukami trial deck to use for their fight. Kai goes over the rules of Vanguard with Naoki as they play. When Kai uses Blaster Blade Seeker, it triggers Naoki's memory, which helps him remember everything including Aichi. Forming a new friendship, Kai and Naoki make a vow to find Aichi. Misaki notes that their fight remains unfinished, but Naoki loses his motivation to keep playing after what just happened. So, Kai asks Misaki if she wants to fight (after noticing Misaki's intrigued look at Blaster Blade Seeker and showing hints of remembering Aichi), and she accepts. In a post-credits scene, Aichi is seen sitting on a throne elsewhere...

(Source: Wikipedia)