The three chipmunks - Alvin (with the voice of Justin Long), Theodore (with the voice of Jesse McCartney) and Simon (with the voice of Matthew Gray Gubler go on vacation with Dave (with the voice of Jason Lee). They take a love-boat like cruise in the areas of the Hawaiian islands accompanied by the Chippettes - Brittany (with the voice of Christina Applegate, Eleanor (with the voice of Amy Poehler) and Jeanette (with the voice of Anna Faris).
Immediately, when they get on the boat, they start to cause troubles. Alvin convinces all the chipmunks to join him in Para-sailing which causes them all to get lost far away from the ship. They end up on an island. Dave follows behind on a hang-glider. On the island they run into Zoe (with the voice of Jenny Slate) who has been stranded there from before. Alvin gets bit by a spider and falls unconscious. When he wakes up he thinks he is French, tells everyone to call him Simon, and cannot remember anything about what happened.
They prepare a raft to get them off the island. During this time Zoe kidnaps Jeanette. Zoe also knocks Alvin in the head turning him back into Simon. Zoe uses Jeanette at the end of a rope to collect treasure from a cave. It is not safe because the island's volcano is very active. Dave and Alvin rescue Jeanette from Zoe. As they escape, Dave almost falls from the bridge but it is Zoe that saves him. The chipmunks perform at international awards for music and Alvin sells his story about the adventure to be made into a film.
Best part of story, including ending:
The chipmunks are so cute, even when they get into troubles.
Best scene in story:
When Alvin awakens for the spider bite thinking he is a French man it is very funny.
Opinion about the main character:
Even though Alvin is Dave's nemesis at times, still he is good friends with Dave.