Doraemon: Nobita's The Birth of Japan

Frustrated by their lackluster real lives and having nowhere to play, Nobita and his friends Gian, Suneo, and Shizuka decide to embark on the greatest mass runaway in history. Meanwhile, due to a disruption in spacetime, a boy named Guu Guu from ancient China arrives in 20th-century Tokyo. He is discovered by Nobita and his group and taken back to 70,000 years ago. It turns out that Guu Guu's Light Tribe was being invaded by the Dark Tribe, whose leader is Jajan, a figure from the future world who seeks to alter the course of history. With the assistance of the Time Patrol, Jajan's conspiracy is ultimately thwarted, and Guu Guu and his tribe migrate to Japan, becoming the ancestors of the Japanese people.