Sugoroku Mutou is the grandfather of Yugi Mutou, who gave him his famous Millennium Puzzle as a present, which he had recovered from the tomb of the Pharaoh Atem in his youth. He owns the Kame Game shop, where Yugi and his friends get several of the games they play, and he taught Katsuya Jonouchi how to play the Duel Monsters card game. His fondness for games is even evident in his name: "Sugoroku" is a Japanese game similar to Backgammon.