The Kingdom Hearts series is infamous for having a long and confusing storyline. That reputation is amplified by the series’ bizarre naming scheme, which misleads many players into assuming they can play Kingdom Hearts, then Kingdom Hearts II, then Kingdom Hearts III, never realizing that they’ve skipped half a dozen important games in the middle. Now, though, all the games have received remixes, Kingdom Hearts III is so close we can taste it, and I’m here to try and explain the plot of the series up until this point.
My goal isn’t to go into every single nitty gritty detail, but to provide an overview that will help new players—or those who haven’t touched the series since Kingdom Hearts II—get a good idea of what’s actually going on. As such, parts of this write-up are intentionally simplified.
Begin reading part one below, covering Kingdom Hearts χ and Kingdom Hearts: Birth by Sleep.
The fairy tale
The story actually starts long before the events of the first Kingdom Hearts, back in the time of fairy tales. The world was full of light, which shone from an object called Kingdom Hearts (title drop), a massive heart-shaped, moon-like thing in the sky that’s said to be the heart of everything. Legend says that Kingdom Hearts was protected by a powerful weapon called the χ-Blade (pronounced like “key-blade”). Wielders of other, lesser, keyblades were numerous.
However, a mysterious cloaked figure named the Master of Masters predicted that the light would expire and the world would end. He appointed each of his six apprentices, the Foretellers, a different task, created cute cat-like spirits called Chirithy to aid keyblade wielders (we know at least one of these is showing up in KHIII, thanks to trailers), and vanished. In his absence, the Foretellers squabbled, manipulated by the tasks he’d given them, and their fight over the world’s remaining light eventually led to the fall the Master of Masters had predicted. Their armies of keyblade wielders clashed in a massive Keyblade War, Kingdom Hearts disappeared, and the world fell into darkness. The χ-Blade split apart into 20 pieces, seven of light and 13 of darkness.
One Foreteller, Ava, had been chosen by the Master to bring about the new world and keep light from expiring. She had gathered her own keyblade wielders that showed potential, and let the light in their hearts create new worlds, all separate from one another, thus forming the multiverse of different Disney worlds the rest of the series takes place in.
Five of these children gathered by Ava became the new leaders, including a boy named Ventus.
Our villain, part one
Still years before Kingdom Hearts I, but in more modern times, a creepy old man named Master Xehanort becomes obsessed with this fairy tale. Master Xehanort thinks the current world is out of balance, formed and ruled by the tyranny of the light rather than a balance of light and darkness. He resolves to fix this by recreating the myth: he would reforge the χ-Blade, summon the seven guardians of light and 13 seekers of darkness, and bring about another Keyblade War in order to destroy the current light-filled world and create a new balanced one.
Master Xehanort’s first attempt to recreate the χ-Blade comes at the expense of his apprentice, Ventus. (To make things more confusing, it’s not yet confirmed how the Ventus from the prologue and this Ventus are connected, and as you’ll see, in this series, them having the same name and appearance may not mean they’re the same person.) Master Xehanort forces Ventus’s heart to split into two parts, one of pure darkness and one of pure light, in the hope that the two sides will fight and their clash will reform the χ-Blade. The light half keeps the name and appearance of Ventus, while the dark half takes a new appearance and the name Vanitas. However, the now pure-light Ventus is left weakened from his heart shattering and nearly dies, while Vanitas’s creation spawns the Unversed, beings that feed on negativity and become the main enemy type in Birth By Sleep.
A tangent: Our first glimpse of Sora, Riku, and Kairi
Master Xehanort takes the fragile, weakened light-Ventus to a world called Destiny Islands to die. The dying Ventus’s heart reaches out and finds a newborn baby named Sora, soon to become the protagonist of the entire Kingdom Hearts series. Their two hearts connect, and Ventus draws on strength from Sora. Though Sora remembers none of it, this meeting ties their two destinies together, grants Sora the ability to wield a keyblade, and imprints the memory (and appearance) of Ventus on his heart.
Since Ventus lives, Master Xehanort decides to keep him alive, though decides he’ll need to be stronger before he and Vanitas can fight. Master Xehanort brings him to the Land of Departure to be trained under another Keyblade Master, Eraqus, while Xehanort continues to train Vanitas.
While studying under Master Eraqus, Ventus meets two other pupils, Terra and Aqua, and the three become strong friends. Ventus can no longer remember anything from his past without great pain from the memory of his heart shattering, and begins training with them to become a Keyblade Master himself.
The trio have several adventures and inadvertently set two more destinies in motion. While on a world called Radiant Garden, Aqua meets a young girl named Kairi, Sora’s future love interest and future Princess of Heart. Aqua casts a protection spell on Kairi that unintentionally guides Kairi to Sora’s world later on, and Kairi touches Aqua’s keyblade, accidentally granting herself the ability to wield one in the future. At another point, Aqua and Terra travel back to Destiny Islands, where they meet Sora and Riku, now grown into young boys. Terra takes a liking to Riku and passes on the power to wield a keyblade to him. These actions, combined with Ventus sharing Sora’s heart earlier, set the stage for Sora, Riku, and Kairi to take up their own keyblades as the main characters of future games.
Back to the actual story: The tragedy of Ventus, Terra, and Aqua (the wise)
But, of course, Master Xehanort is still plotting, so the harmony can’t last long. While Ventus is recovering and training, Master Xehanort shifts his attention to Terra, detecting that Terra has darkness in him that can be manipulated. Master Xehanort and Vanitas set up a series of tricks and traps to drive the trio apart, playing them against one another. Vanitas uses the loss of his friends to try and goad Ventus into fighting, knowing their clash will be key to reforging the χ-Blade.
Through these confrontations, Ventus learns of his true nature, and confronts his teacher, Master Eraqus. Eraqus attempts to kill him in an effort to stop the χ-Blade from reforming. Terra steps in to save Ventus, and Master Xehanort uses his shaken faith in his mentor to drive Terra further into darkness. After the fight, a weakened Eraqus is killed from behind by Master Xehanort, and his heart flees into Terra.
The conflict comes to a head at the Keyblade Graveyard, the site of the ancient Keyblade War. Ventus, now knowing the danger if he fights with Vanitas, asks Aqua and Terra to kill him if they must to prevent the χ-Blade from being formed. Before they can react, Master Xehanort and Vanitas arrive. Ventus and Vanitas are finally forced to face one another, and Ventus’s worst fears are realized. Their conflict brings them back together into one being, and Vanitas is the dominant personality in charge. As their mental struggle continues, the χ-Blade is reborn of their merging.
Aqua joins the attack against Vanitas-Ventus, and succeeds in damaging the χ-Blade. Ventus, still fighting from the inside, chooses to destroy his own heart in order to take Vanitas and the χ-Blade down with him. Both Vanitas and the χ-Blade are destroyed in an explosion of light, and Ventus’s heart leaves his body, leaving him in a comatose-like state. Aqua rescues his body and hides it away in the now-shattered Land of Departure, creating a labyrinth to shelter it. This new structure becomes known as Castle Oblivion.
Meanwhile, Terra and Master Xehanort engage in their own battle. Master Xehanort reveals that he has been attempting to sway Terra towards darkness for his own benefit—he plans to take over Terra’s body in order to gain renewed youth and survive the next Keyblade War. With Terra already halfway corrupted, Master Xehanort succeeds in taking over Terra’s body, though Terra struggles hard enough that his own armor reanimates and fights against Terra-Xehanort. Their struggle is interrupted by the lightstorm that comes from the χ-Blade’s destruction, which sweeps Terra-Xehanort all the way to another world.
Aqua, having left Ventus’s body in Castle Oblivion, tracks them down to Kairi’s world in Radiant Garden. She follows Terra’s heart crying out to her, only for Terra-Xehanort to attack her. Terra is still struggling within Xehanort’s control, so Terra-Xehanort turns his keyblade on himself, trying to get rid of Terra. By accident, this hurls them into the realm of darkness. Aqua gives chase and chooses to sacrifice herself, diving into the realm of darkness after them and throwing Terra-Xehanort back up into the realm of light while she herself descends further into the dark. She can only hope that there’s enough of Terra left to be saved.
Our villain, part two
Terra-Xehanort reawakens in the realm of light, with no memory of how he got there or who he is. Deep within his heart, Terra and old Master Xehanort continue to struggle, with Master Eraqus’s heart granting Terra enough strength to continue despite his partial corruption. On the surface, however, this new body—simply calling himself Xehanort—seems to have no awareness of his situation.
Old Master Xehanort had backup plans, however. Xehanort is quickly surrounded by a number of friends and conspirators to remind him of his nature, gains an apprenticeship to a scientist specializing in research on hearts, and with a new face no one recognizes, is ready to begin his real work on the nature of the heart, the χ-Blade, and Kingdom Hearts.
Stay tuned for the next part, covering the story of Kingdom Hearts, parts of Kingdom Hearts 0.2: Birth by Sleep – A Fragmentary Passage, and parts of Kingdom Hearts II.