Doraemon the Movie: Nobita's Great Battle of the Mermaid KIng

Nobita asks Doraemon to take him somewhere they can dive and as a result the robot-cat uses several gadgets to make it possible for both to able to swim on an imaginary ocean above sea level. Inadvertently a mermaid ends up on Nobita's backyard when they turn off the illusion. Her name is Sophia and she is a princess of an ancient underwater civilization. Doraemon, Nobita, Shizuka, Jyaian, and Suneo quickly become her friends and are invited to visit her homeland. While heading towards the under...