Overview
Doraemon: Nobita and the Legend of the Sun King , also known as Doraemon and the Empire of the Sun, is a 2000 Japanese animated science fantasy adventure film, which premiered on March 7, 2000, in Japan, based on the 20th volume of the same name of the Doraemon's Long Tales series. The film presents a plot similar to the story The Prince and the Pauper by Mark Twain, where Nobita and a prince identical to him switch places.
From Wikipedia (CC BY-SA 4.0).