Naofumi is projected into a world very close to a heroic fantasy role-playing game. But while other heroes have been equipped with formidable offensive weapons, Naofumi inherits a shield with limited capabilities to progress in this game where danger can arise at any moment. Betrayed by his partner and vilified by the population, the young man can now only count on himself to survive in this hostile universe... and perhaps on an idle young girl with unexpected resources.