Dajeongchi Moshan Bame

As an illegitimate daughter, Baek Eun-Chae has never had a life of her own, as she is about to enter an arranged marriage with the son of another prominent family. But one day, Tae Gang-Heon, the CEO of Taesung Group, finds her confronting her fiancee, who was cheating with another woman. From there, her life spins out of control, as Tae Gang-Heon pursues her relentlessly, and they become entangled in a secret relationship.

(Source: Naver, translated)