Mimi-Siku is the son of Michael and Patricia Cromwell. He was born sometime after his parents separated and Patricia moved to the Island of Venezuela.
He sees his father for the first time when he comes to the island to take care of a divorce settlement.
Mimi gives him a tribal nickname "Baboon" as is their custom and Michael agrees to spend time with him and take him to New York someday when he reaches manhood.
At night Mimi undergoes the traditional rite of passage of his tribe, who then considers him to be a man. The tribal elder gives Mimi a special task: to become a tribal leader one day, Mimi must bring fire from the Statue of Liberty and he looks forward to travelling with his father. Michael unsure about the circumstances agrees to take him.
Mimi finds it hard to adapt to life in New York and doesn't get on well with Michael's fiancée, Charlotte who is less than pleased about the unexpected visitor in a loin cloth outfit, who tries to urinate in front of her at a fake tree (as is usual in his tribe), suggests eating her cat, and Maitika, his enormous pet tarantula escapes from his box and into her apartment.
During a trip with his father, he meets and falls in love with Michael's business partner Richard Kempster's daughter Karen who is trying on a bridesmaid dress.
A lot of cross-cultural misunderstandings occur with his father when Mimi-Siku reverts to customs considered acceptable by his tribe. On climbing the Statue of Liberty to reach the flame, he is disappointed when he sees that the fire is not real.
While staying at Richard's house, he eats his valuable, prize-winning Poecilia latipinna fish, much to Richard's frustration so he goes out late at night to catch some more fish to replace them. Karen follows him and they start a relationship with Mimi painting her face and giving her a new name, Ukume, as is the custom in his tribe. He puts the fish back in the tank and they both fall asleep in a hammock in the garden. Richard wakes up and freaks out when he sees them outside and decides to send Karen to a all girls summer camp.
The Kempsters and Michael are later targeted by Alexei Jovanovic, a Russian mobster and caviar dealer, who believes that they have cheated him in a business deal of coffee. Jovanovic arrives at the Kempsters' and tortures Richard for info. Since he refuses, he tries to amputate Richard's fingers in revenge. By fighting together and utilizing Mimi-Siku's hunting skills (and Maitika), the two families fight off Jovanovic's group.
Mimi-Siku returns to Venezula, but before he leaves, he gives one of his earrings to Karen to remember him by and his father gives him a satellite phone so they can stay in touch. Michael also presents Mimi with a Statue of Liberty cigarette lighter, which produces fire from the torch and will fulfil Mimi's quest. In return, Mimi gives his father a blowpipe and poisoned darts, telling Michael to practice and come to see him when he can hit flies.
Back in Venezuela, he receives a call from his father, that he has come to visit him and when he sees him, the two lovingly embrace each other. Michael shows Mimi that he has finally hit a fly with the blowpipe. The Kempsters have also come too on a vacation which reunites Mimi with Karen.