Around the year 2030, Earth has been linked to a parallel world of monsters and magic through a new collectible card game named Future Card Buddyfight. By using a Buddy Rare Card as a portal, normal humans can become partners with a monster and call upon them to battle other players in Buddyfights. As some humans choose to use the power of their Buddy to commit crimes, a law enforcement agency called the Buddy Police tracks down and confiscates the Decks of those who violate the law. Mikado Gaou is an eager young martial artist who becomes Buddies with the hot-blooded Drumbunker Dragon. Receiving a Core Deck Case from Ryuuenji Tasuku, a Buddyfight prodigy working for the Buddy Police, he takes his first steps into the fantastic world of Buddyfight. Source: TV Tropes