Everyone's "Count" is a number based on life choices, but avoid reaching 0 or you'll be sent to the Abyss!.

Alcia is a world governed by "Count": numbers engraved on a person's body, representing any number related to their life. These Counts determine a person's social status and power in Alcia. If a Count reaches zero, the person is sent to the Abyss, a place rumored to be worse than death. Hina, a traveler whose Count is based on the distance she traveled, witnessed her mother get dragged down into the Abyss. Determined to fulfill her mother's last wishes, she sets off on a journey in search of the legendary Aces-heroes of the war that happened three hundred years ago, bearing a white star next to their Count. While wandering around, Hina encounters Licht Bach, a mysterious masked man with negative Count, and Nana, the owner of a tavern. In the midst of having a good time, Hina is tricked into a battle with a military soldier. However, despite his negative count, Licht rescues Hina and reveals that he has another count, one with a white star, one of a legendary Ace. Plunderer follows the journey of Hina and other inhabitants of Alcia as they discover the truth about their world, the Abyss, and the legendary Aces.—MAL Rewrite

Every human inhabiting the world of Alcia is branded by a "Count" or a number written on their body. Depending on how each person lives their life, this Count either goes up or down. For Hina's mother, her total drops to 0 and she's pulled into the Abyss, never to be seen again. But her mother's last words send Hina on a quest to find a legendary hero from the Waste War-the fabled Ace.—Funimation