Nobita dreams of finding a perfect world like in Utopia, and with Doraemon and friends, he discovers Paradapia, a seemingly ideal city run by three sages and protected by Sonya, a perfect cat robot. As the group settles in, they learn from a time-traveling bounty hunter, Marimba, that Paradapia is actually a brainwashing facility created by Dr. Ray to control people’s minds. Nobita resists the brainwashing and helps his friends break free. Together, they stop Ray's plan to enslave humanity, and Sonya sacrifices himself to contain the collapsing Paradapia. In the end, Ray is arrested, and Sonya is later revived with the memory module found by Doraemon, giving hope for their reunion.