Synopsis: One day, Noby discovers a door to a spaceship in the floor of his bedroom. Aboard the spaceship, he and Doraemon befriend Robble, a boy from Planet Arryd, and Chammy, a space creature. In search of a baseball field they can call their own, Noby and his friends visit the spacious Planet Arryd, only to be thrown out by Galtite Mining – a company plotting to take over the planet. Angered by the company’s treatment of their new friends, Noby and Doraemon fight back, soon discovering that Planet Arryd’s low gravity gives them supernatural powers. Utterly powerless against these strange Earthlings, Galtite Mining calls Killerman over from headquarters as a last resort. But Killerman’s plan goes beyond getting rid of the troublesome Earthlings: he wants to blow up Planet Arryd into chunks of Galtite! Can Noby stop him? The second tale of the Doraemon’s Long Tales series!