Dark Yugi is the Yu-Gi-Oh! Toei anime version of the character Dark Yugi, also romanized as Yami Yugi. The Toei anime is based on volumes 1 to 7 of the manga series. Dark Yugi is a spirit who resided within the Millennium Puzzle. When Yugi completed the puzzle, Dark Yugi took up Yugi's body as a host. Occasionally he takes control of Yugi's body to defend him and his friends from bullies and dangerous people by challenging them to dangerous Dark Games. His existence is initially unknown to Yugi, who mistakenly credits memory loss to Dark Yugi's periods of control. Yugi and his friends later learn of Dark Yugi's existence.