HALEY JAMES SCOTT: Haley is a bright student who works at the tutor center at Tree Hill High School. She is childhood best friends with Lucas Scott and wife to Nathan Scott. In the beginning of the series, Haley is an outcast and a nerd but through her relationship with Nathan and her friendship with Lucas she makes new friends including Brooke Davis, and Peyton Sawyer. Haley is a talented singer and in the third season, she makes her own album and goes on tour putting strain on her marriage with Nathan. In the season 4 finale, at her high school graduation while giving her valedictorian speech she goes into labor and gives birth to her son James (Jamie) Scott and names Lucas and Brooke as his godparents. Seven years later she gives birth to her daughter Lydia. Haley becomes a teacher and also helps run Peytons record label, Red Bedroom Records.
PEYTON SAWYER: Peyton is one of the main female characters in One Tree Hill and the main love interest for Lucas Scott. When she first met Lucas she was dating his half brother, Nathan. Peyton and Nathan broke up shortly there after and she began an on-again-off-again relationship with Lucas, which including a complicated love triangle between Lucas, Peyton, and her best friend Brooke Davis. She eventually marries Lucas and the two have a daughter together, Sawyer Brooke Scott.
BROOKE DAVIS: Brooke is a bubbly, popular, and promiscuous cheerleader at Tree Hill High. She had her heart broken twice by Lucas due to his on-again-off-again relationship with Brooke's best friend, Peyton. She is best friends with Peyton Sawyer and Haley James Scott and in high school, Brooke was known to sleep around and had a less than perfect reputation. In her senior year, she created a clothing line called Clothes over Bros which turned into a multi-million dollar corporation.