Nobita wants to run away from home, but every patch of land he tries turns out to belong to someone. When Shizuka, Gian, Suneo and even Doraemon admit they want to run away too, the group travels 70,000 years into the past to build a home in a Japan with no people in it. There Nobita mixes animal genes to create a dragon, a griffin and a pegasus. Then Kukuru, a prehistoric boy swept into the present by a time vortex, turns up hiding in Nobita's closet, with a story of his tribe carried off by the shaman Gigazombie.