Koutetsu no Vendetta Episode 0

After several years in the military, Rain Yashima has grown impatient and frustrated. The Japanese army was not going on the offensive at all, and there was an overwhelming difference in the level of weaponry between them and the enemy army, the Seventh. At this rate, it would only be a matter of time before they lost the war, let alone overturn their inferior position.

Then a ray of hope landed on Rain's doorstep. In her hands is the power to judge history, and in her hands is the power to weave history. The girl abandons her womanhood and vows to fight as steel. Now, Yashima Rain's lonely war begins.

(Source: Video description, Translated)

Note: The project began as a series of doujin shorts by the unit Thumbnail, agreed to produce the anime. The project was announced in 2009 to be produced by the Japanese arm of the French company Ankama Games. Production halted in 2011 due to the dissolution of the production division of its sponsor Ankama Japan, to later release in 2013.
To date, only 1 episode ("Episode 0") has been produced.