Doraemon the Movie: New Nobita and the Castle of the Undersea Devil

The story begins with Nobita, Gian, Suneo, and Shizuka arguing over where to spend their upcoming summer vacation, with the boys wanting mountain camping and Shizuka preferring a tropical beach resort. To resolve the dispute, Doraemon uses his advanced gadgets to create a hybrid camping trip at the bottom of the Pacific Ocean. Equipped with underwater walking liquid, breathing tubes, and specially adapted bicycles, the children marvel at the vibrant marine ecosystem, building an elaborate, hidden undersea base complete with a pool and automated defenses.Soon, the kids encounter a mysterious mute boy named El, who belongs to the ancient Mu Federation—a technologically advanced civilization that secretly survived the sinking of their continent by moving deep beneath the ocean floor. El explains that his people are under grave threat from the neighboring, hostile Atlantis Empire. Atlantis has been dormant for millennia, but its automated defense systems and warlike citizens, fueled by the terrifying, sentient supercomputer Poseidon, are awakening to conquer the surface world and eradicate the Mu civilization.Driven by a strong sense of justice and their growing friendship with El, Nobita and his friends refuse to abandon the undersea world. Doraemon takes charge, deploying an arsenal of futuristic gadgets to fortify their underwater castle against the impending Atlantean invasion. Despite their preparations, the Atlantean forces launch a massive, coordinated assault, utilizing armored vehicles and devastating energy weaponry to breach the castle's defenses.During the chaotic battle, Shizuka is captured by the Atlanteans, raising the emotional stakes for Nobita and the group. Fueled by desperation and fierce loyalty, Nobita steps up, displaying rare courage as he leads a daring infiltration mission into the heart of the Atlantean stronghold to rescue Shizuka and neutralize Poseidon. Doraemon uses his temporal and technological expertise to dismantle Poseidon’s core processing units from the inside, while Gian and Suneo provide crucial tactical cover against waves of Atlantean guards.With Poseidon finally defeated and the Atlantean threat neutralized, the danger lifts from the oceans. The grateful people of the Mu Federation are saved from total annihilation, and peace is restored to the undersea realm. Nobita and his friends bid an emotional farewell to El and their ocean home, returning to the surface world just in time to enjoy the remainder of their summer vacation, forever changed by their epic subterranean adventure.