The story about Nobita meeting with the twin dinosaurs Kyu and Myu, he decided to raise it and become a loving parent despite being different. But in the end, there is a limit where Kyu and Myu could live in modern times.

Nobita with Doraemon and friends decided to travel in the past 66 million years ago and began to find Kyu and Myu friends.

With the help of Doraemon's tools, they arrived at the Cretaceous period which is said the extinction of the dinosaurs is waiting for Kyu and Myu and the fate of Nobita and others.