Tatsumi leaves his remote village hoping to help his impoverished hometown. Won over by the ideals and determination of Night Raid, he becomes the newest recruit in the Revolutionary Army's covert assassination unit. Fighting the Empire brings the naïve boy into conflict with enemy assassins and powerful weapons, while testing his morals and values.
The revolution seeks to overthrow Prime Minister Honest, whose pursuit of wealth and power exploits the child emperor's inexperience. Under this leadership, the nation suffers poverty, conflict and ruin. Night Raid targets those who stand in the uprising's way, but its seasoned killers do not consider their work righteous simply because they believe in the cause. They recognize the gravity of taking lives and expect that they may one day face retribution—a burden Tatsumi must confront as he learns what being an assassin demands.