In an alternate 1930s Europe, the small nation of Gallia holds the last major deposits of a war-fueling mineral called ragnite, drawing an invasion from the neighboring Empire. Recently commissioned militia officer Welkin Gunther, son of the war hero Belgen Gunther, takes command of Squad 7 alongside tank engineer Isara Gunther and scout Alicia Melchiott, who led her hometown's watch before the war reached it. This manga is a loose adaptation of the Valkyria Chronicles video game, and its story parts ways with the game's in places.