The story follows a princess from the kingdom of Elbern, who was sacrificed to seal the demon king. She awakens 300 years later in the northern part of the continent. Deciding to live a new life as a commoner named Serena, she takes a job as a maid at the infamous Valois Duke's castle, rumored to be a terrifying place. There, she encounters a sharp-tongued but endearing girl and the Duke of Valois, known as the "Battlefield Butcher." The narrative explores her journey of adaptation, survival, and the mysteries surrounding her new life.