Yu-Gi-Oh!: The Movie - Pyramid of Light (2004)

Yugi, a smaller than average high school student, and an easy target for bullies, is given an ancient Egyptian riddle called the "Millennium Puzzle" by his grandfather, a local game shop manager. Yugi pieces the puzzle together and unexpectedly becomes the powerful "Game King." Now when Yugi gets into sticky situations, the "Game King" takes over and protects Yugi and his friends.