The narrative opens in the mundane reality of Tokyo, where Nobita, perpetually bullied by Gian and Suneo, desperately seeks a way to escape his daily humiliations. His fortunes seemingly change when he discovers a miniature alien named Papi, fleeing from a tyrannical regime on the distant planet Pirika. Papi is the president of Pirika, overthrown by the ruthless dictator General Gilmore and his oppressive military junta. Soon, Doraemon, Shizuka, and even Gian and Suneo are drawn into the interstellar conflict, miniaturized by Doraemon’s secret gadgets to help Papi protect his fragile freedom.As the group bonds with Papi, constructing a makeshift base in the mountains and playing with advanced
alien technology, the looming threat of Gilmore’s forces draws closer. The primary antagonist, the menacing PCIA military commander Dorkor, dispatches advanced reconnaissance drones to Earth. Despite Doraemon’s technological safeguards, the villains locate Papi by targeting Shizuka, kidnapping her to use as leverage against the young president.Motivated by deep friendship and a sudden burst of genuine bravery, Nobita and his companions refuse to abandon Shizuka or surrender Papi. They formulate a high-stakes rescue mission, piloting custom-built starfighters into the vastness of space. The ensuing space battle highlights the character development of the group; Gian and Suneo conquer their cowardice, while Nobita channels his creative
resourcefulness to outsmart the technologically superior PCIA armada.Upon infiltrating the flagship, the children navigate labyrinthine corridors, dodging laser fire and security forces. They successfully liberate Shizuka in a tense, action-packed sequence, but the victory is short-lived. Papi, demonstrating profound selflessness, surrenders himself to Dorkor to spare his Earthling friends from total annihilation, unwilling to let innocent lives be sacrificed for his rebellion.Devastated yet resolute, Nobita rallies Doraemon and the others to launch a full-scale counter-offensive directly onto the surface of Pirika. Teaming up with the planet's underground freedom fighters, they exploit a critical weakness in the capital's defense grid. In the climactic showdown, Doraemon’s reality-altering gadgets turn the tide against Gilmore’s mechanized legions. Nobita confronts Dorkor directly, utilizing clever tactics to dismantle the commander's battle suit. With Gilmore’s regime dismantled and freedom restored to Pirika, Papi is reinstated as leader. The children bid an emotional farewell to their alien allies, returning to Earth forever changed by their cosmic adventure, where Nobita faces his everyday bullies with newfound, hard-earned inner strength and confidence.