The series takes place during the year 2030, in Choutokyo, Japan. Through the game "Buddyfight", humanity is able to interact with the residents of other worlds: Buddy Monsters. Chosen humans (known as "Buddyfighters") become "Buddies" with Buddy Monsters to play the game. There are those who choose to use the power of Buddy Monsters for evil, but the "Buddy Police" puts a stop to these criminals. Gao Mikado is a student at Aibo Academy, and is a very nice guy, even if he doesn't look like it. His life changes when he meets the son of the hero of the Dragon World: Drum Bunker Dragon (whom he nicknamed 'Drum') that he drew from a pack in class one day.