The Kingdom of Arandas and the Countries Unification of Ingelmia have been fighting a prolonged war, with the Great Wall fortress remaining sealed off. Susumu Tokimune, a new recruit, is eager to participate in his first battle and takes the initiative, leading his platoon into a confrontation with engineer Jamie Hazaford and the advanced mecha, Argevollen. This encounter in a war-torn region sets off a chain of events that will impact not only Tokimune's Independent 8th platoon but also the war's trajectory.