Mary is an outcast princess who cannot use magic.

A political marriage is arranged for her.

Mary optimistically believes she can finally be useful to the royal family. However, at her fiancé's presentation party, her engagement is broken, she is arrested on false charges, and condemned to execution.

Betrayed even by her parents and brother, who arranged her marriage, Mary flees with her older sister, her only ally.

However, they fail to escape and are killed alongside her sister by the 'Arcana User,' the strongest magic user.

But at the brink of death, Mary's power awakens.

The power she gained is the Arcana of the 'Reaper,' which devours corpses to strengthen herself.

Wielding this new ability, Mary vows revenge against all who killed her sister.

Illustrations: Alle

Volume 1 of the comic adaptation is now on sale.

Also available on Novelism and Kakuyomu.