Black Bullet (2014 Anime Series)

In a world ravaged by the Gastrea virus, humanity teeters on the brink of collapse. Enju, a young orphan with the ability to wield the advanced suit known as "Arm Slave," joins forces with Kisaragi, a grizzled Counter, to hunt down and eliminate the monstrous Gastrea. As they navigate the treacherous landscape, they must confront the harsh realities of their world, where survival is a daily struggle and the line between human and monster is increasingly blurred. With their lives on the line, Enju and Kisaragi forge an unbreakable bond in a desperate bid for hope.