Shirogane no Ishi: Argevollen (2014)

in a time of war to countries fight for their own ideals using any means necessary. now there is a new machine to conquer the battlefield called "Trailkrieger" Susumu Tokimune is a new recruit that on his first battle loses his Trailkrieger, but his luck hasn't run out yet. he encounters an engineer with a new Trailkrieger called Argevollen which change the course of war.