After a concert mishap lands Dave in the hospital, Alvin, Simon, and Theodore end up in the care of Dave's twenty-something cousin Toby. When the Chipmunks put aside their stardom to return to school to win a annual "Battle of the Bands" competition to save the school's music program. But the boys meet their match with the Chipettes, Brittany, Jeanette, & Eleanor, who are working for the Chipmunks's ex-manager Ian Hawke. Romantic sparks and crazy mishaps happen when the Chipmunks and Chipettes square off.