Mr. Ryuga is a teacher trainee assigned to Duel fifty students at Duel Academy. On the condition that he could defeat them all, he would be recognized as an official professor of the school. He however had bigger plans in store once he became a professor. He is rumored to take the cards of those he defeats. When he Duels, he cheats by using a special ring to emit an electromagnetic force that disables his opponent's Duel Disk, preventing their use of Spell Cards. He challenges Jaden Yuki, but the Duelist defeats Ryuga with his "Alternate Fusion" Trap Card. Afterward, the ring broke and he lost his chance to become a teacher at Duel Academy.