Crayon Shin-chan: Unkokusai's Ambition

A comical fantasy adventure on a fight against invaders from another world. The ruler of dark world "Don Kurai," Dark, plots to dominate the human world. There is a legend about three treasures and a hero in Don Kurai, and Dark takes over one of the three treasures, a bell of copper, but a man sent other two treasures (a spear of gold and a shield of silver) to the human world. Shinnosuke falls into Dark's trap and opens the door between the human world and Don Kurai, but he becomes the hero selected by the spear of gold. With the power of a girl from Don Kurai, Mata Tami, the Nohara Family transform into various things and fight against Dark.

Shin-chan and his family travel to Samurai's Era by accident and try to save the Princess' city by helping in the war.

From a bleak future, Shinnosuke Nohara sends a girl named Tamiko on a mission to bring his five-year-old self to that time period right before being captured. Reaching the past, she claims to be Shin-chan's bride and takes him and his friends on a wild adventure to try to save the world to come.

As the 21st century approaches, a new 20th-century museum has opened in town, for the adults to relive their childhood. However, the owners of the museum seem to have other plans for it. The adults start to behave strangely, and one morning, they abandon their children for the 20th-century museum. Shinnosuke, along with his friends, must now rescue his parents and stop the world from returning to the 20th century before they get captured.