One day, Nobita opens a tiny rocket from which the miniature alien Papi steps out. He hails from the world called Pirika, fleeing his planet"s PCIA forces. Initially Doraemon and companions are baffled by Papi"s diminutive stature, yet with the device "Small Light" they shrink and play together in a playful adventure under the neon lights. Still, a whale‑shaped warship that pursued Papi arrives on Earth and assaults Doraemon and Nobita to seize him. Papi apologizes for dragging everyone into danger, but he vows to confront the PCIA army with courage. To safeguard Papi and Pirika, Doraemon and friends travel back to that planet, determined to protect their new ally.
