The hero of Dragon Quest Monsters: Joker is a member of the secret organization CELL who wishes to compete in the Monster Scout Challenge.
The story first finds him in a jail cell for defying the leader's orders to participate in the contest. Soon, however, the leader gives him an assignment: join the tournament, though there is a hint that there are more orders to come.
Soon after, he encounters the Incarnus, who also has a mysterious interest in the contest.