Doraemon: Nobita and the Birth of Japan

Overview

Nobita, thinking of running away from home, travels back in time with Doraemon and his pals to prehistoric Japan. However, a time paradox causes prehistoric boy Kukul to land in the modern day, so it's up to Doraemon and the rest to help the boy get back to the past while also defeating the mysterious shaman king, Giga-Zombie.

Full Plot (Spoilers)