A young teenage girl, Katie, can not snap out of her depression after losing her mother. Katie has lost interest in school, her friends, and gymnastics. All that changes in the summer when she is asked to monkeysit Gibby, her science teacher's Capuchin monkey. Taking care of the monkey changes her life in a big way. Gibby's happy-go-lucky personality renews Katie's zest for life. Gibby helps her with gymnastics, renewing friendships (including finding a potential boyfriend) and overcoming her nemesis, a mean girl who is out to beat Katie at everything.

Crystal the Monkey
as Gibby

Shannon Elizabeth
as Ms. Martin

Peyton Meyer
as Tommy

Shelby Lyon
as Katie

Ysa Penarejo
as Alicia

Sean Patrick Flanery
as Frank

Vivica A. Fox
as Director

Tess Kartel
as Coach

Eryn Nicole Pablico
as Diane

Sabina Bacino
as Cindy