Moto Ansatsusha, Tensei shita Kizoku no Reijou ni Narimashita.  

元暗殺者、転生して貴族の令嬢になりました。, Moto Ansatsusha, Tensei Shite Kizoku no Reijou ni Narimashita, A Former Assassin Was Reborn as a Noble's Daughter

Meet serena, an ex-assassin who was reborn as a duke's daughter after failing her mission. initially, she believed that posing as a noble would be effortless, but she grappled with the contrast between herself and her mother, who had a flamboyant personality, and her adopted sister, who deceived others to push serena out of the spotlight. despite skillfully evading the harassment at tea parties full of rivalry and navigating the intricate social life of a school entangled in love and hate, serena's icy disposition led to her being shunned and isolated. one day, she discovers that her adopted sister is betrothed to the second prince, prompting her to flee from home. however, it is at this moment that evan, the first prince, emerges before her, marking the beginning of serena's journey into the aristocratic society of a new realm in this humorous and occasionally romantic narrative.