The Final World is an original world introduced in Kingdom Hearts III. It serves as the destination for those whose hearts and bodies perished together, but continue to persist due to something (or someone) holding them from death.
Settings and Areas
The Final World is composed of a semi-cloudy sky and an aqueous soil that seem to extend to infinity. In a "certain zone" of this world, the aqueous soil is replaced by a multitude of pillars and crystalline cubes which form a kind of labyrinth floating in the air, and which, when a person falls, immediately brings it back to the same place from the sky, a little like a sort of "infernal loop". It is possible to turn the labyrinth in one direction or another by hitting "glowing cubes" scattered throughout the area.
According to Chirithy, the Final World would be on the border between sleep and death, which makes it very easy to access from the Sleeping Worlds and the Dive to the Heart. More generally, it is in the Final World that those whose bodies and hearts have perished together, but who do not want or can not die for one reason or another, reside.
Between Kingdom Hearts and Kingdom Hearts 3D: Dream Drop Distance
Since Sora only passes unconsciously into the confines of the Final World every time he goes to Dive to the Heart, Chirithy always tries to watch him without ever intervening.
Kingdom Hearts III
Sora arrives here after being overwhelmed by a massive Demon Tide created by Terra-Xehanort at the Keyblade Graveyard. Immediately after arriving in The Final World, Sora encounters a Chirithy. According to Chirithy, this is not Sora's first time here, but rather the only time he arrived involuntarily and therefore he cannot just leave on his own accord as he could with previous visits. Chirithy continues explaining that usually only the hearts of people whose hearts and bodies perished together, but still have someone or something clinging to them, end up in The Final World. But that Sora, who still has fragments of a body, must have somehow had not only his heart but also his body cast into this world. In order for Sora to return to his friends, he must first gather the pieces of himself that are scattered around the world.
While running around gathering his body fragments, Sora encounters the hearts of many people telling him their stories.
One of the hearts that Sora speaks to tells him that her heart belongs to no one, that "they" took away her name and everything about her. Sora tells her there is no way anyone could take away her heart, and she replies with "only because it pines for another." She explains that she isn't certain if anyone will come for her because the one she pines for, his heart has been changed and replaced with another's, but that if he were to regain himself then he would be distraught by her absence. So she waits in case he ever seeks her out. Sora tells the heart to keep believing and not lose hope that this person will come for her. Sora wishes to help her but realizes his own situation means he has too much to do, and she iterates that he must first solve his own problems. She guides Sora, telling him that he has a strong sense of purpose and that he will find his direction in that. Sora asks for the persons name that she is waiting for and she whispers in it his ear, Sora gasps, recognizing the name. She tells him that this is their secret and he leaves.
Another heart Sora encounters is Naminé's. She explains that she was in Kairi's heart, but when they were struck by the Demon Tide, she awoke here. She tells Sora that Kairi is okay, but that she's fighting with all her strength to keep Sora from fading away and that is why his body ended up in The Final World. Sora doesn't want to leave Naminé behind, but she reassures him that as soon as Kairi is safe then she will return to Kairi's heart. Sora tells Naminé that he wants to thank her, but not until she has her body back. Naminé states that it's okay if she doesn't get her body back because she isn't the one everyone misses, that Roxas is the one they miss. Sora tells her she's wrong, that he, Kairi, the King, Donald, Goofy, Roxas, and "someone special" want to see her again. She thanks Sora, telling him that she has been sifting through Terra's memories and that he is still tethered to the realm of light, and that she will do her best to bring him back.
Sora then goes through a portal to a structure made up of blocks covered in fragments of his body doing various things: some dancing, some flying, some running around. After Sora finds all his fragments, he once again goes through a portal and Chirithy reappears. Chirithy tells Sora that it's time for him to leave. But before he goes, Sora asks who it is that Chirithy is waiting for. Chirithy refuses to say as the person he's waiting for doesn't remember anymore and that he's sure this person is much happier with their new friends. Despite that, Chirithy chooses to wait because he's sure this person will arrive in The Final World some day. Sora tells Chirithy that he'll be back to visit because they're friends now, much to Chirithy's surprise and delight. As Sora is leaving, he turns to ask Chirithy how to save his friends, he tells Sora that he should already know how to restore someone's heart, and Sora opens a portal using the Keyblade. Chirithy tells Sora to look for the light in the darkness and may your heart be your guiding key, and Sora leaves.
After the final battle against Master Xehanort, Sora and Kairi arrive at the Final World, due to Sora's sacrifice after using the power of awakening without learning to control it; he begins to fade. Sora starts yelling for Chirithy and Chirithy reappears before them, claiming to leave them alone for a moment. Both decide to accompany the Chirithy to meet his friend again.
At the end of Kingdom Hearts: Melody of Memory, Kairi is plunged into a deep sleep, where searching for the memories of her heart, she finds a connection that led her to Sora. She then she remembers something that happened to her when she was little; she was cornered by Heartless and abducted by Xehanort, taking her to the ark where he transported her to the Destiny Islands. After fighting the ghost of Master Xehanort, she discovers something important: Sora appears to help her, but he finds himself in a place on the other side of reality. Kairi, Riku and the Fairy Godmother return to this world, to search for the "third key" (the key to Kairi's memories and the key to Riku's dreams) that, according to the Fairy Godmother, they could help them find their way to Sora. They find the Nameless Star, who proceeds to the other side of reality, in a fictional world called Quadratum. Riku uses the power of awakening with the Nameless Star to travel to Quadratum and find his best friend.
- When the Final World appeared in one of the Kingdom Hearts III trailers, it was speculated by many fans that this was the place shown on the Kingdom Hearts II Final Mix cover.
- Due to its connection to dreams, Fairy Godmother is well-versed about this world. She can come and go from it with little effort.
- Finally, the Nameless Star is revealed as a person on the other side of reality, in a fictional world called Quadratum, where Sora could be.