Doraemon: Nobita at the Birth of Japan(1989)

Doraemon: Nobita no Nippon Tanjou

The 10th Doraemon movie.

Nobita wants to run away from home, again. He finds out that there is nowhere for him to go. All the land is owned by someone. His friends end up wanting to run away also, even Doraemon. They figure out that the only way to find land that isn't owned by anyone is to go back in time to when no humans existed. They end up helping a prehistoric boy rescue his tribe from Gigazombie.