Michael Cromwell(Tim Allen),is a self-absorbed,successful commodities broker,living in New York City. Wanting to marry his new fiance,Charlotte(Lolita Davidovich), he needs to obtain a final divorce from his first wife,Patricia(JoBeth Williams),who left him years earlier. Patricia now lives with a semi-westernised tribe in Venezuela. Michael travels there to get her signature on divorce papers,but,upon arriving,discovers he has a 13 year old son,Mimi-Siku(Sam Huntington).
Michael attempts to bond with Mimi-Siku in his brief stay with the tribe,and promises to take him to New York'when he is a man'. That night,Mimi-Siku undergoes the tradition rite of passage,of his tribe,who then consider him to be a man. The tribal elder gives Mimi a special task,to allow him to become a tribal leader one day. Mimi must bring fire from the Statue Of Liberty,and looks forward to traveling with his father. Michael brings Mimi-Siku to New York.
Michael's fiancee,Charlotte,is less than pleased about the unexpected visitor,particulary when he suggests eating her cat and releases his pet tarantula in her apartment. Michael attempts to adapt Mimi-Siku to city life. On climbing the Statue Of Liberty,to reach the flame,Mimi-Siku is disappointed when he sees that the fire is not real;
While Mimi-Siku is staying at the home of Richard Kempster(Martin Short),Mimi falls in love with Richard's daughter,Karen(Leelee Sobieski). Richard is unhappy about Mimi's presence in his home,because of his influence over Karen.
Mimi-Siku returns to the Amazon jungle,but before he leaves,his father gives him a cell phone,so they can keep in touch. Michael also gives Mimi a Statue Of Liberty cigarette lighter,that produces fire from the tourch. 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.
Michael finds himself disheartened by the rat race and realizes his relationship with Charlotte isn't working for him anymore. Michael returns to Lipo-Lipo to see his son and ex-wife,bringing the Kempster family with him for a vacation. Karen and Mimi are reunited,and Michael and Patricia decide to get back together.