Three chipmunk brothers, Alvin, Simon, and Theodore are adopted by human, Dave.
The origin of the Chipmunks is revealed, including how Dave ended up with the Chipmunks in the first place, as well as how their musical career got started.
Alvin and Simon have Theodore enter a wrestling exhibition under the name ""Mr.Fabulous"" and he goes up against a montrous Russian wrestler called Ivan The Terrible.
The Chipmunks meet their grandparents for the first time. Then, when they discover that someone is trying to take over their Grandparents farm, they decide to raise the money needed to save the farm.
Alvin convinces Theodore to dress up as an alien to attract more fans, but they also attract some investigators with the government who research ufo's. The investigators decide to kidnap Theodore and perform experiments on him and Alvin and Simon must think of a way to save him.
Alvin, Simon, and Theodore go in search for a mother to attend their school picnic. Each choose the person, that they each think Dave will like best. But, when all three of their choices arrive at their house, Alvin, Simon, and Theodore, will do anything to make sure that their choice wins.
Alvin decided to change the Chipmunks image to gain more publicity, but end up running from the police, when they attend a rave.