When Nobita feels like diving in his hometown, Doraemon uses a Underwater Pump Simulator to pump all the water out of Tokyo, causing the entire city to go underwater. That night, Doraemon and Nobita use a Diving Mask Simulator to dive underwater. Later on, lots of fish, and a shark attack Doraemon and Nobita. So, Doraemon puts a stop on the Underwater Pump Simulator, but there is a girl named Sophia, lying down on the bushes in his neighborhood.
Where To Watch.
Currently Doraemon: Nobita's Great Battle of the Mermaid King full movie is available for streaming online, rent, buy or watch for free on: HBO Max
Doraemon: Nobita's Great Battle of the Mermaid King (ドラえもん のび太の人魚大海戦, Doraemon: Nobita no Ningyo Daikaisen) is a 2010 Japanese anime feature film based on the manga and anime series Doraemon. The film was released in Japan on March 6, 2010. It is the thirtieth film to feature the character Doraemon.