What comes to the end of war, unlimited development and environmental destruction.
Nobita and his friends came to the planet of the animals through the mysterious pink gas. It is a beautiful planet that 100% of a living infrastructure is supplied by clean energy sources. The dog boy "Chippo", who met there, is planning to explore the forbidden forest in search of ancient artifacts.—tama
Nobita dreams that he entered a mysterious pink gas and into a forest, where he finds all the animals talking to each other. He finds a flower and takes it back to the gas. The next day, Nobita tells everyone about the dream, but they do not believe him. Nobita returns home to find the flower inserted into a vase.
The night, Nobita goes to the bathroom and discovers the mysterious pink gas for real, and enters it. He arrives to the forest and is caught in a thunderstorm. Doraemon saves him just in time, and Nobita tells him about the animals. They find a little dog caught in the thunderstorm while sailing in a river and they save him. Nobita and Doraemon bring the dog, Chippo, back to the city where he is reunited with his father, as well as other animals, who can also talk and behave like humans. Chippo's parents invite Nobita and Doraemon for tea, before they had to go home. On their way back to Earth, they notice another planet larger than the Moon, and it can only be accessed from the pink gas. Doraemon fixes the machine and they return home.
In the afternoon, Nobita hears from his friends that they are listening mysterious voices. When he goes back to his home, he founds that the voices are coming from the String less phone.
Nobita tells Doraemon that he can use his gadget, but Doraemon refuses. After Nobita gives him the Star Flower, Nobita, Doraemon, Shizuka and Suneo prepare for going to the Animal Planet. But Suneo wants to go with Gian. Gian comes and says that it became too long to prepare for him. After they go, they found that Chippo was in grave danger. The Nimuges had attacked their planet and captured Chippo's cousin, Romi-Chan. Doraemon gives Nobita a gadget named "Lunar Luck" for which he was incredibly lucky.
Nobita Boarded the Star Ship and goes to the Nimuges' planet. Nobita hits a nimuge and puts on his clothes. But the head realizes that some spy was with them and orders them to be lined up to be checked for as spies. Before they could reveal Nobita as the Spy, another Nimuge was revealed to be a spy working for the space police force. Asked to escort him to the cell that Romi was held in, the police turns the tables with the help of Nobita as Romi and Nobita escape just in time. The Nimuge then states their intentions, that they are an offshoot of humans who had squandered their planet's resources and resorted to scavenging to survive. One of the methods used to save what's left of nature was by transferring the animals through the teleportation gas and making them sentient, allowing them to create a new society that would respect nature. The remaining Nimuge however desired to take the planet for themselves and has prepared an invasion fleet to take and colonize the new land.
Nobita and Doraemon prepares a defense against the invaders at the dawn of the next day. Using the air cannons they were able to disable most of the ships and forced them to land as Doraemon improvises when it their guns failed to penetrate the environmental suits. Forced to retreat, the Nimuge commander orders a scorched earth attack on the forest but another fleet of ships approaches from behind. To the relief of the animals and Doraemon they are the Galactic police force who had been searching for these men as they are part of the Cockroach organization who was led by a young man whose family harbored resentment towards the animals for living in paradise through the millennia. The Galactic Nimuge expresses their regret for their actions and their desire to make amends with the animal planet. With the help of the Animal planet, they were able to head home back to Japan.