A new student named Duke Devlin defeats Joey in a game of Duel Monsters and forces Joey to become his reluctant servant. Duke orders Joey to wear a dog costume and humiliates him in public, leading Yugi to challenge Duke to a duel in order to free Joey from his enslavement. Duke accepts Yugi's challenge, but tells him that instead of playing Duel Monsters, the two of them will be playing a game called Dungeon Dice Monsters, which Duke created himself.