Yugi has his old life back, the life without the Millennium Puzzle, without the evil Ramsis and of course, without Yami. But when familiar faces suddenly appear in Domino City, he starts doubting if his dream about the adventure was really a dream, or that it might all have been real.

Atem and Yami Sennen are brothers, and happen to be demons. They were cast into the underworld by a spellcaster thousands of years ago. Zorc is the King of the Underworld, and is enjoying his reign and the havoc he is wreaking on the surface. However, Zorc has been notified that there is a pure light on the surface that will mess up his plans if not stopped soon. This light has an artifact Zorc needs to complete his plans...a golden pyramid. When Zorc sets up a competition between the two brothers to go to the surface, destroy that light, and retrieve the pyramid, the demon brothers have little interest. When Zorc tells them that the prize is to become mortal again, both eagerly jump at the challenge. What will happen to the brothers...and to the light?