The world was in ruin from the invasion of the Void Beasts, but with their arrival came a hope. Artifacts from a different world appeared to give humanity the fighting power needed to fight back against the invaders. Years passed since the invasion to the point where humanity has collectively recovered, but still need to fight off the Beasts on a daily basis. On the Western Continent, a deserter named Tancred Adams is punished by joining the 13th Squad, a team infamous for its high death rates to the point only the squad leader lives to tell the tale. Determined to fulfil a promise, he vowed to stay alive, regardless of what the world throws at him.