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.