In the past, Ryuji Otogi’s father had lost in the shadow tournament. As a sequence, he wanted him to take revenge on Yugi Mutou as well as his grandchildren. For that reason, Otogi teamed up with Pegasus to create Dungeon Dice Monsters in order to challenge his enemies. They used the Millennium Eye to eavesdrop on opponents’ thoughts and tactics, but once again took defeat.
