A stray dog turns out to be royalty from a hidden empire deep in Africa, and suddenly Doraemon's usual suburban chaos has to survive actual stakes. The first hour moves slow, but once you cross into the Smokers Forest, the movie earns every detour through hostile terrain and extinct-looking wildlife. What makes this one stick is how it finds genuine danger in a world that was supposed to be safe the moment the gadgets showed up.
Nobita rescues a stray dog wandering the streets and decides to keep him as a pet. What he doesn't realize is that this dog is actually royalty from a hidden kingdom deep within Africa's mysterious Smokers Forest, a place where dogs have evolved into a sophisticated civilization with their own government and culture. When the dog's true identity surfaces, Nobita and his friends embark on an adventure to return him to his homeland before it's too late. They pack their gear, gather Doraemon's gadgets, and head into uncharted territory. Upon arrival, they discover that the kingdom has fallen into turmoil during the prince's absence. Political upheaval and danger threaten the dog empire from within, and the friends find themselves caught between protecting their new companion and navigating the complex conflicts of this strange world. Their simple mission to reunite a prince with his home becomes an expedition into adventure, danger, and unexpected friendships that test their courage and ingenuity in ways they never anticipated.