The drama revolves around two individuals: one consumed by vengeance since childhood, and the other, who assumes someone else's identity after their death to fulfill two promises. These promises include repaying a debt of help and seeking revenge for the death of the person whose identity they've taken, as well as meeting the deceased's sister.

Throughout the series, the connection between these two characters and how they navigate their missions are explored. While the acting is commendable, the initial episodes may seem slow-paced.