No adults appear on the series.
Chris William Martin (Dylan Blackwell) and Ryan Reynolds (Billy Simpson) are the only actors to appear in both the first and last episodes of the series.
The entire first season only has seven different sets: the school hallway, the Avalon, Brooke's bedroom, Dylan's garage, the boys' locker room, the girls' locker room, and Billy and Courtney's apartment.
Chris William Martin (Dylan Blackwell), Todd Talbot (Matt Walker), Laura Harris (Ashley Frasier) and Ryan Reynolds (Billy Simpson) are the only actors to remain with the series throughout its entire run.
Laura Harris (Ashley Fraiser) appeared in season 2 using her middle name, Elizabeth as a first name and appeared in season 3 using her first name, Laura and her middle initial, E. and appeared in seasons, 1 and 4 using only her first name, Laura.