Sweeping across the globe, the card game Cardfight Vanguard has influenced many to incorporate card games into their daily routines. Enthusiasts of this popular title are known as "cardfighters," and they often compete against one another in card shops. The game has inspired numerous individuals, including the quiet and timid Aichi Sendou, who is frequently mocked and bullied by his classmates. Whenever he feels discouraged, he looks at Blaster Blade—a legendary rare card given to him in his youth—and finds the motivation to continue with his life. However, one day, school bully Katsumi Morikawa spots Aichi's treasure and snatches the card from him. Following a series of events, Aichi soon learns that the card is now in the possession of Toshiki Kai, a cardfighter who has become the strongest in town despite having only recently arrived. To make matters worse, Kai refuses to return the card unless Aichi defeats him in a cardfight. To everyone's surprise, Aichi rises to the occasion. As he gathers his courage and imagines himself winning this decisive battle, Aichi begins to find his way into the adventurous world of Cardfight Vanguard.