While enjoying a futuristic space action game borrowed from Doraemon, Nobita is startled when a real miniature spaceship suddenly crashes into his room! A tiny robot emerges from the spacecraft, introducing himself as a loyal servant of Princess Arle from the planet Lilliput. He begs Nobita to help rescue the princess, who has been captured by the space invaders known as the Akanbeaders. When Nobita learns that Princess Arle is a beautiful girl who looks just like Shizuka, he sets off to confront the Akanbeaders and save her... But what awaits him on this extraordinary adventure?