Melony, a girl who grew up in a fake prison and endured a miserable life in orphanages and on the streets, awakens a mysterious Repair Ability and is eventually kidnapped and killed. However, she regresses to the age of four, back to her life in the prison. Determined to survive a happier life, she befriends an undercover investigator to avoid her former fate. But things take an unexpected turn when she becomes the fake daughter of a notoriously eccentric duke!