In the year 1935 E.C., the continent of Europa is dominated by two superpowers: the autocratic East Europan Imperial Alliance in the east and the democratic Atlantic Federation in the west — both economies dependent on the precious multipurpose mineral Ragnite. As that mineral grows scarce, the Empire declares war on the Federation, igniting the Second Europan War, and swiftly puts the Federation on the defensive. Emboldened, the Empire decides to invade the neutral Principality of Gallia to seize its rich Ragnite deposits.
When Imperial forces strike the Gallian border town of Bruhl, Welkin Gunther — son of the late national hero General Belgen Gunther — is forced to fight for his life alongside the town watch captain, Alicia Melchiott. Together with Welkin's adopted sister Isara and his father's prototype tank, the Edelweiss, they escape to the capital and join Gallia's militia. Given the rank of lieutenant, Welkin takes command of the newly formed Squad 7, with Alicia as his NCO; though the squad doubts his inexperience at first, his tactical brilliance soon wins their trust and loyalty — and he and Alicia grow ever closer.