In the first film, Doraemon and his friends travel to prehistoric times where they meet Kukuru, who's tribe has been enslaved by Gigazombie. Doraemon must help him save his tribe and stop Gigazombie's terror.
In the sequel, many years have passed, and Doraemon and friends returns to prehistoric time to see Kukuku. They go on a new adventure where along the way, Nobita and friends meet their ancestors.
