森の中でビデオを撮影していたのび太たちは、中に小さなロケットを発見、パピという宇宙人と知り合いになる。パピはピリカ星の大統領で、反乱軍からのがれるために地球にやってきたのだった。
パピを守ることに決めたドラえもんたちは、スモールライトで小さくなるが、反乱軍からスモールライトを奪われ、しずかを人質に取られてしまう…！
Papi, the tiny president of a faraway planet, escapes to Earth to avoid being captured by the military forces that took over. Despite being welcomed by Doraemon, Nobita and their friends, the little alien notices that his enemies have also reached this world and doesn't want to get his human friends involved in this war. Doraemon, Nobita, Gian, Suneo, and Shizuka start a big adventure as they try to hide and protect Papi.
