The series is about having hope and faith in for the characters and Duel Monsters on each cards. Yugi's grandfather Sugoroku Mutou (Solomon Muto) owns a game shop. One day, Yugi finds a strange puzzle at the back of the shop, and tries to solve it. He tries to solve the puzzle for 8 years. When he is 16, he solves it. When he finishes the puzzle, he gets an extra soul. The soul is Dark Yugi (Yami Yugi), an Egyptian Pharaoh. Yami Yugi successfully recovers his lost memory. Yugi defeats Dark Bakura (Yami Bakura), Dark Yugi's worst enemy. Yu-Gi-Oh; cards of Doom