Driven by the relentless pressure of nagging parents and repetitive daily scoldings, Nobita resolves to run away from home. Joined by his loyal friends Gian, Suneo, and Shizuka, who share equally stressful domestic grievances, Nobita aims to find a pristine, uninhabited paradise where they can establish an independent civilization. Unable to find a suitable location in contemporary Tokyo, Doraemon uses his futuristic gadgets to transport the rebellious youths back in time, seventy thousand years ago. In this prehistoric era, Japan is completely untouched by modern humanity, offering vast, fertile wilderness and boundless freedom for the children to build their dream utopian society.Equipped with advanced futuristic tools, the kids construct a lavish, automated cave dwelling and genetically engineer a bizarre menagerie of hybrid pets, including a winged pegasus, a dragon-like creature, and a humanoid griffin. However, their idyllic vacation comes to an abrupt halt when they encounter Kurukuru, a primitive boy from a displaced Neolithic tribe. Kurukuru reveals that his people were violently enslaved and driven from their ancestral lands by the Gigazombie, a ruthless, time-traveling conqueror from the 23rd century who plans to alter history and claim ancient Asia as his personal empire.Fueled by a newfound sense of
responsibility, Nobita and his friends transition from carefree runaways to fierce liberators. They vow to protect Kurukuru and defeat the tyrannical invader. Doraemon orchestrates a tactical resistance, utilizing high-tech gadgets disguised as tribal magic to rally the scattered primitive villagers. Tensions rise as Gigazombie deploys his superior futuristic weaponry and mind-control technology to crush the uprising. In the ensuing climactic battle, Nobita demonstrates
unprecedented bravery, confronting Gigazombie directly to safeguard the timeline and protect his new prehistoric friends.The struggle reaches a fever pitch when Gigazombie traps the group, threatening to erase them from history permanently. Working together, Doraemon and the children outsmart the villain's security systems, ultimately destroying his time-distortion machinery and neutralizing his forces. With the dark overlord defeated and handed over to the 23rd-century Time Patrol, the primitive villagers are finally safe to rebuild their lives in peace. Having grown immensely through their trials of survival, leadership, and sacrifice, Nobita and his friends bid an emotional farewell to Kurukuru and their prehistoric creations. They return to the present day, forever changed by their grand adventure, viewing their modern homes with renewed appreciation, maturity, and a secret bond forged across tens of thousands of years of human history.