The Chipmunks and the Chipettes are transferring to a new high school in New York. There, they meet some new friends and reunite with an old one. Things are not well at their new school, however, as the local mean girl, Sunset Shimmer, is determined to make their lives a misery.

Can the youngest Chipette, Eleanor, get through her thick skull, and can the fashion diva, Rarity, convince Brittany to think of someone other than herself for once?