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. The Chipmunks put aside their stardom to return to school to win an annual "Battle of the Bands" competition to save the school's music program, but they meet their match with the Chipettes: Brittany, Jeanette, and Eleanor, who work for the Chipmunks' ex-manager, Ian Hawke. The Chipmunks and the Chipettes square off; romantic sparks and crazy mishaps ensue.