In the ancient Mesoamerican kingdom of Mayana, a queen sits on the throne until an evil witch, Ledina, puts her into an eternal sleep. The rule passes to the queen’s son, Prince <Tio> Tio, as the story opens. When the queen finally awakens, the balance of power shifts and destiny hangs in the balance between magic and modern life.
The film then jumps to contemporary Japan, where <Nobita Nobi> Nobita Nobi and his friends are rehearsing Snow White for a school play, aided by Doraemon’s gadgetry Doraemon. A string of miscasts derails their practice, and trouble compounds when Gian Gian selfishly seizes the gadget to stage an imaginary stadium show. In response, Doraemon, <Nobita Nobi>, and <Shizuka Minamoto> Shizuka Minamoto attempt a rescue through a time portal, but Gian’s violent outburst shatters the portal—unwittingly opening a connection to Mayana.
The chaos deepens when Tio’s jerboa-like companion, <Popol> Popol, stomps through Nobita’s room and drags his test papers into the forest, forcing Nobita and Doraemon to pursue him through the broken doorway. Along the trail, Nobita is cornered by <Tio>, discovering a startling likeness between the two, and a deadly confrontation nearly ends in tragedy before the two crash into a mud-lake—where Tio realizes that Nobita is not a threat but a friend. The two cross the portal together, while Doraemon and Shizuka stay behind with the others. Nobita is captured by guards who mistake him for Tio, and a clever ruse leads to a temporary friendship of convenience as Tio—awed by modern technology—agrees to swap identities with Nobita for a time.
Life in Mayana proves starkly different for Nobita, who must endure the palace’s rigid rituals and martial-arts training that come with being a prince. Yet Nobita’s warm, open nature gradually reshapes the court, contrasting with Tio’s usual arrogance. He befriends <Kuku> Kuku, Tio’s childhood companion who harbors a quiet crush on the real prince. Her gift of a necklace, offered to “Tio,” becomes a symbol of the new alliance Nobita forms with the people of Mayana, aided by Doraemon’s gadgets and a hope that the curse laid by Ledina can be broken.
Back in Japan, Tio’s volatile temper proves dangerous, prompting Gian to feel a sharp end to his bravado and causing Shizuka to condemn Nobita’s behavior. Doraemon exposes the swapped identities to restore balance, and the group heads back to Mayana—with Nobita donning the prince’s attire and the necklace from Kuku—to help save the realm. The party’s daring rescue includes Gian’s aid after Ishumaru, a loyal ally, appears to have survived a perilous fall. Nobita, in a bold move, uses a switching handkerchief and the necklace to outwit Ledina, replacing Kuku with a stone statue and evading capture.
Ledina’s fury grows as she seeks to sacrifice Tio to gain endless youth under a solar eclipse, while burning Doraemon’s four-dimensional pocket and dispatching a warrior henchman to attack Gian. Ishumaru returns to lend his strength, helping Gian fend off the assault. With Nobita’s quick thinking and a spare pocket, the plan hinges on distracting Ledina long enough to reclaim Kuku and disrupt the ritual. Though Nobita is captured, the people of Mayana rally to free him, and Tio reveals his willingness to sacrifice himself for his friend—an act that embodies the power of friendship.
A Blinding moment comes when the sun hits Kuku’s necklace, momentarily blinding Ledina and giving Nobita a chance to slip away with Doraemon’s help. Ledina’s ritual begins to crumble, unveiling her true elderly form, and she activates the temple’s self-destruct system in a final bid to seize control. The heroes are saved when Ledina’s condor is turned friendly by Doraemon’s Momotaro dangos, and Kuku is rescued from a sleep that lasts until the kingdom’s curse can be fully broken. A kiss from Tio awakens Kuku, and the sleeping queen herself rises to proclaim that Tio will succeed her as ruler.
With Mayana’s fate secured, Nobita and his friends learn that the portal is weakening and may never connect to Mayana again. Farewells are bittersweet as Nobita says goodbye to Tio, acknowledging the enduring lesson of friendship across worlds. In the after-credits, Nobita and the others resume their Snow White play, with Gian and Shizuka stepping into new roles, reminding viewers that teamwork and compassion can bridge even the widest divides.
