The regime of Pirica was subjected to a coup d'état launched by the dictatorial general Gilmoya (voiced by Nobuo Yamaguchi). President Papi (voiced by Keiko Han) was forced to flee from Pirica and landed on Earth by accident. At this time, Nobita (voiced by Noriko Ohara) and others were filming the movie "Small Space Wars" and accidentally discovered the fleeing Papi. During the conversation, they learned that Papi was only 10 years old and graduated from college at the age of 8. Everyone also learned about his experience and decided to help him and became good friends with him. The Gilmoya army found Papi's whereabouts through a small reconnaissance aircraft and attacked Nobita and others. They took Shizuka hostage. In order not to implicate everyone, Papi finally surrendered to the rebels. Pappy's beloved dog Chubby (voiced by Mitsuo Yuji) found Pappy's location through his sense of smell, but unfortunately he made a mistake and happened to meet Doraemon and others. They planned to rescue Shizuka and Pappy and set off to Pirika together, but what kind of adventure will be waiting for them on the unknown planet...