Barrymore plays Josie Geller, a journalist who goes undercover as a high school student to get a juicy story for her newspaper. Her high school days were not so great, so fitting in as a high school student might be harder than it looks. 

Arquette plays Rob Geller, Josie's brother who was a popular baseball player in the prime of his high school years and turned into a nobody once he graduated. Similar to Josie, Rob also pretends to be a high school student to relive his glory days.

Shannon plays Anita, Josie's co-worker. Anita is down for the journey of Josie going back to school and enjoys the ups and downs along the way. 

Reilly plays Gus, the head of the newspaper, Josie's boss. He is skeptical of her new assignment so he watches her every move along her new journey. 

Sobieski plays Aldys, the first person to befriend Josie at her new school. She plays a brainy student that is not in with the "it" crowd. As a result, Josie has to distance herself from her in order to infiltrate the popular crowd and get a better story.

Whalen plays Merkin, the inadequate assistant to Josie at the newspaper firm. Any chance he has to slack off or not do his job, he does. 

Vartan plays Sam Coulson, a high school English teacher that Josie develops a crush on.

Alba plays Kirsten, head of the popular crowd. She makes life hard on Josie when she arrives to her new high school.

Shelton plays Kristin, a popular girl at Josie's new high school. Josie has to pretend to be friends with for the sake of her job. 

Franco plays Jason, a popular guy at Josie's new high school and Kirsten's boyfriend.

Spencer plays Josie's co-worker at the newspaper firm. She watches Josie's journey while she is on assignment.