Under the belief that the omnipotent god Mitama will come to save him, Yukito Urabe participates in a ritual to become the new leader of his father's cult. But when the boy drowns during the ritual, he wishes to be reborn in a world without gods or religion. Reawakening in a completely different world devoid of spirituality. He meets a deviant girl named Aruaru, who introduces him to her village. However, his idyllic image of this world's society is short-lived when he witnesses a public group suicide and learns of the country's end-of-life system: at any moment, the government may order any citizen to die. Aruaru and her sister are forcibly taken for execution soon after, prompting Yukito to rush to their rescue—but to no avail. In a moment of desperation, Yukito recalls his father's teachings and utters a prayer for Mitama to save them. Seemingly answering his call, a little girl descends from the sky and annihilates everyone who harmed Yukito and his friends. To Yukito's surprise, the girl introduces herself as Mitama.

Jealous of Suneo's new robot toy, Nobita asks Doraemon to build him an even better one. Doraemon initially refuses, until Nobita accidentally discovers pieces of a mysterious robot that falls from the sky. After gathering all the robot parts and assembled them together, the giant robot, Zanda Claus, is soon completed. The duo soon learn that the robot is not a mere toy, but a powerful weapon in the fight against the coming Robot Army that is going to attack Earth and enslave the human inhabitants of it. An invasion is near, as a mysterious girl Riruru (リルル, Alternative spelling: Lilulu, Lillele [Doko Demo Doa Scanlations]) shows up, looking for the robot. (Source: Wikipedia)

The plot revolves around a summer vacation of Nobita and his friends under the waters of Pacific Ocean. Jaian and Suneo take Doraemon's underwater vehicle and travel through the Atlantic Ocean, trying to find a treasure ship. Along the way, they discover that the environment gun that Doraemon used to protect them is running out of energy leaving them vulnerable to the sea. Fortunately, they are rescued by some marine creatures. Doraemon and his friends are later captured by these creatures, revealed to be inhabinats of the underwater kingdom of Mu. It is revealed that another undersea kingdom, Atlantis, now controlled by robots, was about to destroy the Earth with nuclear weapons after mistaking a volcano eruption for an invasion. With the help of a young boy from Mu, Nobita and his friends attempt to stop the robots, but are all captured. However, when things are at their grimmest, Doraemon's robotic underwater vehicle sacrifices itself to destroy the computer that controlled all the robots and nuclear weapons. After returning to Mu, Doraemon and his friends are hailed as heroes. (Source: Wikipedia)

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. (Source: ANN)