Irregular Hunter X: The Day of Sigma
English name: Megaman X - The Day of Sigma
Genres: Action, Sci-Fi
Type: OVA, Episodes: 1
Aired: Dec 15, 2005
Studio: Xebec
Source: Game
Rating: PG - Children
Synopsis:
The year is 21XX. Reploids are commonplace now, after Dr. Cain rediscovered Dr. Light's old lab and based several designs off of Dr.Light's original, called "Megaman X." X, meanwhile, has joined the Maverick Hunters, and works with unit leader Zero under the command of General Sigma. It is their job to terminate rogue reploids, those who have become violent. 

(Source: ANN)