The assassin who failed in his mission was reincarnated as the daughter of a duke, Serena. "I'm a former assassin. It's easy to impersonate." I was frustrated and felt her life was difficult. Serena, who is shunned and isolated because of her coldness, while furiously dodging her harassment from those around her, learns of the engagement of her step-sister and her second prince, and she finally runs away from home. to decide. But then, the first prince, Evan, appears-!?