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.[1] It's the 30th Doraemon film.