The movie starts with a boy who belongs to prehistoric times hunting a fish. Returning home he finds it destroyed and cries out in despair before suddenly being captured into time vortex. Meanwhile in the 21st century, Nobita wants to run away from his home due to his mom always scolding him for getting a 0 on tests, as depicted many times in various episodes. As a result of failing to find an ideal home, Nobita decides to make a makeshift place to live, however due to land property ownership laws he fails to find a suitable location. At the same time, Shizuka, Gian, Suneo and Doraemon also want to run away from their homes as they feel their parents have been working them too hard (with the exception of Doraemon, who leaves as the family has been requested to take care of a hamster which Doraemon thinks looks too much like a mouse, an animal he hates). Nobita suggests that they should go back in time to live in a place before humans existed. The group agrees with him and travel to Japan 70,000 years ago.