After disbanding post a fierce national tournament, Team Q4 disperses to their mundane routines. Aichi Sendou, during a visit to Card Capital, encounters a mysterious customer. When Aichi introduces the boy to Cardfight Vanguard, he discovers his deck has transformed entirely, featuring unfamiliar units. Despite the team's claims of consistency, Aichi is perplexed. The enigmatic boy vanishes mysteriously, deepening Aichi's confusion. As Aichi adjusts to his peculiar new deck, he delves into uncovering the truth behind the boy and the unusual turn of events.