Nobita finds a stray dog and brings him home, little does hi knows that the dog is actually a prince in his homeland, a world appart deep in the african 'Smokers Forest' were the dogs evolved and have their own empire, so he and his friends take on a journey to take back the young prince to his homeland but when they get there things have changed.
One day Doraemon, Nobita, Shizuka, Gian and Suneo were shooting a film as space heroes. When they were shooting the film in the open lot a boy called Aron comes and alerts them of aliens attacking his planet. They agree to help him by turning into real superheroes, but it isn't as easy as it looks.
Nobita and Doraemon find a giant robot in pieces which they later assemble. It turns out to be a destructive weapon and the gang must save Earth from an imminent invasion.
