The Rules for Taming a Rose / He Was Never Just My Brother

"After her parents died, she discovered her father had an illegitimate son named Chen Si with his mistress. She insisted on taking Chen Si into the Song family, acting tough and cold, determined to keep him by her side. At first, Chen Si refused to obey and resisted repeatedly, but he gradually fell for her amid her occasional tenderness and vulnerability. Whether the two are blood-related has become the biggest mystery in their relationship."