Zero is one of the main characters in the popular Mega Man (in japan, RockMan) X series and Mega Man Zero series video games. In the X series he is one of the highest ranking "Maverick Hunters" who is fighting to stop Sigma's forces of infected reploids, known as mavericks, from exterminating humanity.

Game History Though Zero's full origins are as yet unknown, they are hinted at in one of the many ending of Mega Man 2 The Power Fighters . If a single player beats this game using Bass a dialogue between Bass and Dr. Wily. Bass is informed that Wily is working on a new robot that will replace Bass as Wily's strongest creation. A silhouette of this robot is shown and it appears to be Zero. Bass laughs at the new robot as "girlie-looking" and "long haired." No more is mentioned on the subject in the Mega Man Classic series.

In MegaMan X, he saves the main character, X, from the hands of a powerful maverick known as Vile. Later on, when X battles Vile again, Zero sacrifices himself to destroy Vile's ride armor. In MegaMan X 2, an organisation called the "X hunters" reveals to X that they plan to find the parts of Zero and restore him as a genral in Sigma's army. X then has to collect the parts of Zero before the X hunters do. Whether or not these objectives are met, when X goes to face sigma, a black Zero is standing by his side. If X did not collect the parts, Zero attacks X, but if X did collect the parts, it turns out that the black Zero was a copy, and the true Zero dispatches him with his new Z Saber, which becomes his signature weapon. Either way, after the Black Zero is defeated, he tells X the way to Sigma's lair.

Later, at the beginning of Mega Man Zero, Zero is discovered in suspended animation by a human scientist named Ciel who leads a band of reploid freedom fightes. Ciel uses the Cyber Elf Passy to revive Zero who saves Ciel and joins here team in fighting the current oppression of reploids. His adventures in this time period are covered in the Mega Man Zero Series.