In the world of Alcia, a person's value is measured by their "Count", a number inscribed on their body which represents key aspects of their life. The higher one's Count, the greater their social standing and power. However, if one's Count hits zero, they are sent to the dreaded Abyss, a place rumored to be worse than death. Hina, a traveler whose Count is tied to distances traveled, watched in horror as her mother was dragged into the Abyss. Driven to fulfill her mother's last wishes, she embarks on a journey to find the fabled Aces: heroes who fought in a war three hundred years prior and whose Count is marked by a white star. While on her quest, Hina meets the enigmatic Licht Bach, a masked man with a negative Count, and Nana, the proprietor of a local tavern. Amidst the revelry, Hina is unwittingly drawn into a fight with a military officer. Despite his own negative Count, Licht comes to her aid and reveals that he has a second Count: one with a white star that marks him as one of the legendary Aces. Plunderer chronicles the journeys of Hina and other inhabitants of Alcia as they unravel the mysteries of their world, the Abyss, and the fabled Aces.