David Sewell (Jason Lee) is a frustrated songwriter in Los Angeles. He works hard day and night, but his works are never appreciated by record company owners. One day, an angry David was furious at home. At this time, three chipmunks from the mountains, Irwin (voiced by Justin Long), Simon (voiced by Matthew Gray Gubler), and Theldo (voiced by Jesse McCartney), broke into David's life. David was surprised to find that these three naughty little guys could not only talk, but also sing in harmony. So he and the little ones reached an agreement that they could live at home, but they had to sing songs written by David, and the interesting story unfolded... The film won the 2008 Children's Choice Award for Most Popular Film.