Doraemon Movie 10: Nobita no Nippon Tanjou  

Doraemon the Movie: Nobita and the Birth of Japan, Doraemon: Nobita at the Birth of Japan, 映画 ドラえもん のび太の日本誕生

Nobita decides to leave home once again, but he discovers that all of the land has already been claimed by someone else. His friends, including Doraemon, also want to escape. After considering their options, they determine that the only way to find unowned land is to travel back in time before humans existed. During this journey, they assist a prehistoric boy in rescuing his tribe from Gigazombie.