Related anime: Yu-Gi-Oh! GX, Yu-Gi-Oh! 5D's

Yu-Gi-Oh! (lit. "Game King") is a Japanese manga created by Kazuki Takahashi. It has spawned a franchise that includes multiple anime shows, a trading card game and numerous video games. Most of the incarnations of the franchise involve the fictional trading card game called Duel Monsters (originally known as Magic & Wizards), where each player uses cards to "duel" each other in a mock battle of fantasy "monsters". The Yu-Gi-Oh! Trading Card Game is the real world counterpart to this fictional game on which it is loosely based.

Story: Yugi Mutou, a shorter-than-average high school student, was given the fragmented pieces of an ancient Egyptian artifact, the Millennium Puzzle, by his grandfather. Upon reassembling the Puzzle, he is possessed by another personality who is later revealed to be the spirit of a 3,000-year-old Pharaoh (5,000-years-old in the English anime) called Atem, with no memory of his own time. As the story goes on, the two of them (together with Yugi's friends), try to find the secret of the Pharaoh's lost memories and his name, with the Duel Monsters card game being an ever prevalent backdrop or plot device.

(source: Wikipedia)