Kakumeiki Valvrave

Year 71 – Revolutionary Calendar, a new era where the vast majority of humanity has taken up residence in space.

The world is divided into two major powers: the "Dorssia Military Pact Federation" which has seen its power grow thanks to military alliances, and "ARUS" (Atlantic Rim United States) which, for its part, has seen its power grow thanks to trade agreements. War rages between these two powers.
In addition to these two superpowers, there are smaller nations that claim neutrality, such as JIOR, where our hero, Haruto Tokishima, studies.
However, his student life is about to change completely when Dorssia decides to attack JIOR to get its hands on a mysterious mobile armor prototype called Valvrave.