Doraemon: Nobita and the Legend of the Sun King

Making use of a secret tool called "Dimension Hole", Doraemon and Nobita go to the ancient kingdom of sun and meet the prince who looks exactly like Nobita. The queen, bound by a curse cast by a witch, is unable to wake from trance. Nobita and the prince decides to swap their lives, while an adventure, which spans over this dimension, is about to begin.