To deceive the demon lord who fell in love with me, I’ll take my selfish sister’s place! — If it means escaping that house, I’ll even take the hand of a devil. Since her father’s remarriage, Count’s daughter Arishe has endured a life of misery, abused by her stepfamily. Stripped of freedom and never knowing love, her fate changes dramatically because of her stepsister Rose. Rose, who has been proposed to by Lord Solfa, a man feared on the battlefield as the “Demon of the West,” detests the engagement and forces it upon Arishe instead. Seeing this as a chance to break free from her wretched life, Arishe disguises herself as Rose and heads to Solfa’s domain as her substitute. However, upon their first meeting, Lord Solfa immediately sees through her disguise, saying— “You’re not Lady Rose, are you?” And thus begins a fateful, dangerous, and unexpectedly romantic deception between a demon lord and a girl desperate for freedom.