As always, the husband's show-off made Nobita angry. In order to help Nobita realize his wish of diving, Doraemon turned the whole city into a virtual ocean and used props to attract creatures in the ocean. A mermaid came to the city, but was trapped by mistake. Her name is Sophia, the princess of the mermaid family. It is said that the mermaids lived on another planet five thousand years ago, and the peace-loving people took refuge on Earth because they were invaded by another race, and have taken root here ever since. Nobita and Shizuka soon became good friends with Sophia and promised to help her find the mermaid legendary treasure "Mermaid Sword". While the friends are playing heartily in the deep sea, the danger comes unexpectedly. The alien demons who invaded the hometown of the mermaids also came to the earth to look for the sword of the mermaids. My friends are about to start a new adventure. This film commemorates the 30th anniversary of Doraemon's theatrical version.
6.5
