Once upon a time, in the 22nd century, Parzival was the emperor of the Oasis, a virtual world.
In the 22nd century, the Earth looked like a big trash. Humans were trying to find a way to escape reality, so they created the Oasis.
Parzival won the game set up by James Donovan, the creator of the Oasis, that was made to define who will keep and control the Oasis at his death.
The principal enemy of Parzival was the company 101, lead by Colin Sorento.
Colin Sorento employed a lot of intelligent people to try to resolve the riddle made by James Donovan to win the game and so the control of the Oasis, but he also uses slaves to track people in the Oasis.
But Parzival was determined to win the game to keep the Oasis safe and to make sure Colin Sorento wouldn't have the control of it because Sorento wanted to make people pay to have access to the Oasis.