KAREN ROE: Karen is the mother of Lucas Scott and former high school sweethearts with Dan Scott. Dan chose his basketball career over Karen leading to their break up and causing Karen to raise Lucas as a single mother. Karen owns her own cafe, Karen's Cafe and is also business partners with Deb, running the nightclub TRIC. Karen had a complicated relationship with Dan's older brother, Keith. He helped Karen raise Lucas, and they were eventually engaged before he was murdered. They did however, have a child together with Karen finding out she was pregnant just before his death. They had a daughter, Lily Roe Scott.
KEITH SCOTT: Was the older brother of Dan Scott and love interest of Karen Roe. He also served as a father figure for Lucas as he was growing up. He was murdered by his brother Dan during the school shooting, which deeply affected the community of Tree Hill for years to come. He also has a daughter with Karen Roe, but he passed away before he ever found out she was pregnant.
LUCAS SCOTT: Lucas is the son of Karen Roe and Dan Scott, and the half brother of Nathan Scott and nephew to Keith Scott.. He was raised by his single mother with help from his Uncle Keith and is a main character of seasons 1-6. He is best friends with Haley James Scott, and is also the godfather to her first child with Nathan, James (Jamie) Lucas Scott. Lucas has also had many relationships including a long term love triangle between himself, Brooke Davis, and Peyton Sawyer. In the later years after graduating from Tree Hill High School he eventually marries Peyton Sawyer and they have a daughter, Sawyer Brooke Scott.