After reincarnation following a past car accident, Adelaide Chamille Borbon leads a mundane life as a nobleman's daughter in the countryside, craving adventure before an arranged marriage. Eager to meet a black-haired woman from another realm dubbed a 'saint,' she rushes to the capital's debutante ball. Meanwhile, Felix Mikhail Noah Elias grows weary of rumors linked to the alleged saint. Unveiling her deceitful nature, she manipulates him with false tales and seduction attempts. Desperate to rid himself of this troublesome figure and salvage his reputation, Felix seeks an engagement with a noble lady promptly. Their paths cross, leading Felix to propose a fake betrothal to Adelaide. Despite his insistence on emotional detachment, proximity challenges his resolve, blurring the lines of their agreement.