Naofumi finds himself catapulted into a world that resembles a heroic fantasy role-playing game. Unlike the other heroes, who are given powerful offensive weapons, Naofumi is left with a shield of limited function to advance in this game where danger can appear at any moment. Betrayed by his teammate and denigrated by the locals, the young man can only rely on himself to survive in this hostile world... and possibly on a young girl in distress with hidden talents.