「天国は雲の上にある！」と信じているのび太のために、ドラえもんは、雲の上に自分たちの夢の国“雲の王国”を作ってあげることに。
そんな中、のび太たちは、気絶している少年を発見。だが、翌日、少年は消えてしまった。彼の行方を追っているうちに、のび太たちは雲の上の天上世界に迷い込んでしまう。
そこには、なんと、進んだ文明を持つ天上人が住んでいた！
Doraemon launches its ecological adventure to save Earth from a terrible threat with Nobita and his whole gang. This time Doraemon used his inventions to create, along with Nobita, his own world in the sky, a giant cloud. During their journey to the cloud are alien beings who seek to destroy civilization to chasten humans for their lack of commitment to the environment. Doraemon and the gang must find allies and convince the people of the clouds on Earth that there are people who fight for nature. In his adventure, meet good friends, raffled countless dangers, will encounter prehistoric animals and will give everything to defend our planet.
