After Shion Kiba performs a ceremony to formally become the heir of the Kiba family, word spreads that their corporation is under threat of a takeover. Shion is contacted by an individual using the pseudonym "Ace" involved in the takeover, who manipulates him into a cardfight using pack fight rules, with the Kiba family's corporation on the line. Shion is able to keep up despite the disadvantage of an unfamiliar format, but Ace uses psychological tactics to discourage Shion and defeats him. Ace reveals that he was broadcasting Shion's failure, in order to discredit the Kiba family and secure the success of the takeover. Later, with his family's wealth and status lost, Shion vows to get to the bottom of Ace's schemes.