A gadget mishap during play rehearsal sends Nobita Nobi and his friends into Mayana, a hidden Mesoamerican kingdom, where Nobita meets Prince Tio, who looks exactly like him. The two agree to trade places, sending Tio into modern Japan while Nobita takes up royal duties. The switch puts Nobita in the path of the witch Ledina, who put Mayana's queen into an eternal sleep and now wants to capture Tio to seize his throne. Doraemon, Shizuka Minamoto, Suneo Honekawa, and Takeshi Gouda help Nobita hold Ledina off before the truth of the swap comes out.