Brooding, troubled protagonist who is taken in by the wealthy Cohen family in Newport Beach after a life of hardship in Chino, California, and navigates a new world while dealing with his past. Tough but compassionate outsider who is fiercely protective of those he cares about, particularly his adoptive brother Seth Cohen, and eventually becomes an architect.

troubled princess" of Newport Beach, who comes from a wealthy but dysfunctional family and struggles with emotional issues, substance abuse. Despite her privileged life, she is deeply vulnerable and often self-destructive, making impulsive choices. Appears perfect on the surface but is emotionally unstable, rebellious, and prone to risky behavior like drinking and drug use. She is empathetic and often tries to "save" others, which leads to more problems.

Witty, fast-talking, and socially awkward son of Sandy and Kirsten Cohen, Seth became a cultural icon for "indie" and "geek" culture in the early 2000s. Known for his neurotic yet self-assured personality, Seth is a fan of comic books.

Initially introduced as a minor, stereotypical "mean girl" and the best friend of Marissa Cooper. Over time, she reveals hidden depth and intelligence, eventually shedding her "party girl" image to become a committed environmental activist and high-achieving student.

Initially portrayed as a manipulative and obsessive overachiever, her character develops into a more complex, emotionally needy, and supportive figure.