Universe of Kingdom Hearts

In the Universe of Kingdom Hearts, also called the World, there are many worlds that fall into certain realms. All of these realms are on their own plane of existence.

History
Legend has it that long ago, in the "age of fairy tales", the world was whole and full of light. The source of the world's great light was Kingdom Hearts, which was protected by its counterpart, the χ-blade. Ancient beings known as were locked in eternal battle with the light, but they cast off their physical forms to infect hearts of people. Over time, people succumbed to these negative emotions and came to desire the power of Kingdom Hearts, giving rise to the first Heartless.

The first Keyblades were forged in the image of the χ-blade by those who wished to conquer or protect Kingdom Hearts. These ancient wielders clashed together in a far-reaching conflict that embroiled the entire World: the first Keyblade War. In the end, darkness covered the World, the χ-blade was shattered into twenty pieces – seven of light and thirteen of darkness – and the "true" Kingdom Hearts disappeared into the darkness.

However, the world was restored by the light within the hearts of children. The many worlds that were split apart in the Keyblade War were reformed, each with its own time flow; the worlds were surrounded by barriers that prevented outside interference and inter-world travel. The remnants of the battlefield on which the Keyblade War took place became the Keyblade Graveyard, a scarred wasteland filled with the Keyblades of fallen warriors. The remaining Keyblade wielders resolved to protect the World from further destruction, becoming guardians of the world order.

While there still exist methods to travel between worlds, most individuals do not posses the knowledge or capability to do so. Those few who do travel between worlds are advised to avoid meddling in the affairs of other worlds and informing their inhabitants of the existence of other worlds.

Ocean Between
The Ocean Between, also known as the "ocean of stars" or "interspace" (星の大海) and the "sea between worlds" or "Other Sky" (異空の海),  is a vast space between the worlds. It is threaded by the Gummi routes and, which serve as paths between worlds for those with the knowledge to use them.

Travel
Traveling between worlds is normally very difficult. In addition to being separated by the Ocean Between, worlds are also protected by barriers which prevent outside interference.

With the barriers in place, only certain people – such as Keyblade wielders with access to Lanes Between, users of Corridors of Darkness, or powerful sorcerers – can gain access to other worlds. However, when Heartless attack a world, these barriers are broken, indicated by a meteor shower in that world; the barriers are restored when the worlds are restored and their keyholes locked. Without barriers, anyone who can survive and navigate the Ocean Between can travel between worlds. The various methods of travel are often facilitated through the use of a Gummi Ship or Keyblade Glider.

Lanes between
The Lanes between (異空の回廊) are a series of "roads" between the worlds used by Keyblade wielders. The presence of darkness is very strong within these pathways, forcing travelers to wear their Keyblade Armor as a safety precaution. To enter the Lanes, a wielder typically raises their Keyblade and creates a portal in the sky or in front of them; powerful wielders, such as the Foretellers, can create these portals without their Keyblade on hand.

Corridors of Darkness
The Corridors of Darkness (闇の回廊) are pathways that interlink the various worlds, as well as connecting the Realm of Darkness and Realm Between to the Realm of Light. They may only be opened by those who have given themselves over to darkness, but can be used by almost anyone once opened. The Heartless and Nobodies frequently attempt to link their own Corridors to the gates. Corridors of Darkness also occasionally form spontaneously within the Realm Between, often when a world is destroyed and its surviving inhabitants are cast away.

When Heartless use dark corridors, they appear as brief orbs of dark energy that they drop out of; when Nobodies use them the corridors instead take a bright white appearance.

While nearly anyone can use the Corridors, frequent use will erode one's body, so those who rely on the Corridors, such as Organization XIII, wear black coats to protect themselves. Those without the coats can survive occasional exposure to the Corridors' darkness if their hearts are strong enough. They wear this to give themselves protection from being devoured by darkness.

Gummi routes and Gates
Pieces of Gummi known as "Star Shards", or the Gummi Ships built from them, are able to travel the Ocean Between. Using Gummi Ships is much easier, as single Star Shards will cause random jumps if their handler isn't skilled in their use. Although the closely-guarded lanes between already allowed some limited travel between worlds, the gummi routes were made ubiquitous when the Heartless first began destroying the walls between worlds, leaving enormous holes that made it possible to travel for anyone who could get their hands on Gummi. The holes also made it possible for anyone to travel without the assistance of Keyblade wielders.

However, when the walls between the worlds were restored with the destruction of End of the World, Gummi Ships became all but useless. In response, the worlds themselves prepared the Gates (ゲート) as new pathways, or "highways", for Sora and his friends to travel. The Gates allow their users to travel between worlds despite the presence of the otherwise impassable walls between them, making them similar to the. The first Gate known to be used, leading to the Land of Departure, was opened by the Wayward Wind after Aqua rescued Ventus's comatose body. As Yen Sid informs him, Sora is able to unlock them when his Keyblade reacts to a specific object significant to its world, opening a new Gummi route. Though after Kingdom Hearts II, these new paths sealed themselves.

After Sora's failed Mark of Mastery exam, he travels to Olympus alongside Donald and Goofy by opening a Gate simply by using his Keyblade, without an item triggering it. Once Master Xehanort obtains the χ-blade, he is able to open Gates without items triggering them, which he uses to separate the Guardians of Light from each other. Soon after, Sora opens a Gate to locate Kairi, by using the crystallized pieces of her heart that Xehanort had held captive in Scala ad Caelum as his trigger.


 * Triggers for the gates:
 * Kingdom Hearts II
 * Hollow Bastion: The Hollow Bastion Restoration Committee honorary Membership Card given to Sora by Leon.
 * The Land of Dragons: Shan-Yu's sword.
 * Beast's Castle: Beast's rose.
 * Olympus Coliseum: The Olympus Stone.
 * Disney Castle: The Cornerstone of Light.
 * Port Royal: Jack Sparrow's compass.
 * Agrabah: A ruby from the Cave of Wonders.
 * Halloween Town: Jack Skellington's Santa Claus costume.
 * Pride Lands: Mufasa's cloud apparition.
 * Twilight Town: The blue Crystal Orb from the Struggle Trophy.
 * Realm of Darkness: The sea-salt ice cream given to Sora by Riku.
 * Atlantica: A bubble.
 * Kingdom Hearts III
 * Scala ad Caelum & Keyblade Graveyard: The crystallized fragments of Kairi's heart.

Time Travel
It is possible to travel through time, but only if a person casts their heart from their body. Time travel is a rare occurrence, and few individuals possess the knowledge or power to travel through time.

When one is traveling through time, there must be a version of the traveler at the destination time period. Once a heart has traveled through time, it must have a body to remain in the destination time period (such as a Replica) or must be in a state that does not require a body (such as being a Heartless). If the physical form that the heart is inhabiting is destroyed, or if the time traveler's heart is otherwise forced out of it, the heart will return to its original time period. The traveler is left with no memories of their time travel, although their experience will still be engraved within their heart and may unconsciously influence their actions.

Through the use of a device called a lifeboat, it is possible to separate a heart from one's body and send it forward through time. Unlike the previous method of displacing one's heart, this method of time travel allows one's entire self to travel forward permanently. Instead of having a vessel at the destination, the time traveler's body is reformed. While this forgoes the need for a version of the traveler at the endpoint, it requires two other things at the destination: a medium – some sort of object with a connection to the traveler – and someone with memories of the traveler. However, if the process is incomplete, the traveler may be left without memories of their original time.

There are also special methods that allow the user to break the rules of standard time travel. These are unconventional and isolated instances that are not typically possible. Special cases of time travel include Yen Sid's manipulation of time to send Sora and Riku to Destiny Islands at the beginning of their Mark of Mastery exam, Young Xehanort's ability to freely travel with his heart and body after being visited by his future Heartless Ansem, and Sora's abuse of the power of waking to first undo the events at the Keyblade Graveyard and then return a second time to piece together Kairi's heart. Certain worlds may also have special time-bending properties, such as Timeless River, a world from Disney Castle's past summoned by Pete's desire to return to simpler days, and the Secret Forest, a world whose time flow has been altered by Merlin and the Three Good Fairies.

Stars
In the ' games, each Star''' is a specific world. Should a star stop shining, that would mean that a particular world has disappeared from existence, most likely from destruction by the Heartless.

In Kingdom Hearts, many stars disappeared. In Mickey's first letter to Donald, Mickey mentions the fact that the stars have been disappearing, one by one, and that he left to find the cause. When Donald and Goofy first arrived at Traverse Town, they discovered a star corresponding Destiny Islands fade out of existence. Some of them were restored after Sora and his friends stopped Ansem's plan to plunge the world into darkness, but others remained submerged in sleep as part of the Sleeping Worlds.

In Kingdom Hearts II, Mufasa implies that there are stars to represent certain individuals as well, such as when he told young Simba that all the great kings of the Pride Lands are looking at them in the form of stars. Years later, Simba tries to reach out to his deceased father, and he appears to him immediately. The same implication happens in Kingdom Hearts Birth by Sleep, when Master Yen Sid detects that "Eraqus's star has blinked out," after he was struck down by Master Xehanort.

Realm of Light
The Realm of Light (光の世界) is the portion of the universe with an affinity for light and is positioned opposite the Realm of Darkness. The majority of the Keyblades in the Kingdom Hearts series are Keyblades of the Realm of Light. The Realm of Light is the primary setting for the series, although the protagonists sometimes travel to the Realm of Darkness, the Realm Between that connects them, or the Sleeping Worlds that lie parallel to them all.

Door to Light
The door leading from the Realm of Darkness to the Realm of Light is called the Door to Light (光の扉). It is one method by which individuals from the Realm of Light may pass from the Realm of Darkness back into the Realm of Light, as Sora and Riku did after finding Kairi's Letter.

Realm of Darkness


The Realm of Darkness (闇の世界) is a realm that lies opposite the Realm of Light. Few are able to survive in the Realm of Darkness; it is instead inhabited by the Heartless and other dark beings. The only known Keyblade of the Realm of Darkness is the Kingdom Key D, wielded by Mickey. The Kingdom Hearts of Worlds' Hearts began growing in the Realm of Darkness after the Heartless plague was unleashed on the Realm of Light.

Door to Darkness
The Door to Darkness (闇の扉) is the dark counterpart of the Door to Light. It is a tall, white door that lies within Final Door, at the End of the World created by the Heartless, and can only be opened by the Princesses of Heart. Beyond the door is the Realm of Darkness where their artificial Kingdom Hearts of Worlds' Hearts resides. Only those from the Realm of Darkness, without light in their hearts, may pass through the Door to Darkness.

After the battle with the World of Chaos, Ansem, Seeker of Darkness opens the door and asks that Kingdom Hearts fill him with the power of darkness. He is instead destroyed, as Kingdom Hearts is the power of light; Sora and Mickey, with the help of Riku, Donald, and Goofy, close the Door to Darkness.

Realm Between
The Realm Between (狭間の世界) lies on the boundary between the Realms of Light and Darkness. Few worlds exist within it, and most have some special nature or purpose.

As of now, Traverse Town, Land of Departure /Castle Oblivion, Twilight Town, Mysterious Tower, and The World That Never Was are the only worlds confirmed to exist within the Realm Between. Each world ties closer to the Realm of Light or the Realm of Darkness, with the exception of Twilight Town, which exists exactly in the middle.

Realm of Sleep
The realm of sleep, sometimes referred to as the realm of dreams, is a place that can usually only be entered when someone is asleep or unconscious, though it is sometimes possible to physically travel there under certain circumstances. It contains the worlds of dreams and memories, such as Dive to the Heart, which are directly influenced by the dreaming individual. Anything that happens in these worlds can also affect the waking world. The Final World, being on the edge of reality just before a heart ceases to exist, is nested closely to the realm of sleep. Those who dream have a chance to catch a glimpse of The Final World, as Sora does when he begins his journey.

The Sleeping Worlds (夢見る世界) are worlds submerged in sleep. They are worlds that fell into darkness but were not fully revived following the defeat of Ansem, Seeker of Darkness for unknown reasons. Because this created barriers, not even the Heartless could penetrate, darkness took a new form in the Sleeping Worlds, known as the Dream Eaters. Sleeping Worlds can only be entered when someone dives into the realm of sleep.

Datascapes
Datascapes are realms made from data where "data worlds" exist. A data world may be created using data from a real world, thus creating a digital replica of that world, or may be programmed to be unique. Data worlds cannot be reached via the Ocean Between, as they exist within computers. Instead, they typically must be accessed via an interface within the world that contains them.

The Other Side
The other side, or what Ansem the Wise termed "Unreality" and hypothezied as a world of fiction, is a world that exists on the other side of reality. During her year long sleep, Kairi searched her memories in an attempt to find a clue to Sora's whereabouts. She ultimately found a memory of Terra-Xehanort sending her to Destiny Islands when she was a child, where he describes a world that is "neither of light nor darkness, but somewhere on the other side". This, along with Riku's dreams of Sora, lead them to the Final World, where the Fairy Godmother introduces them to the Nameless Star, who is an inhabitant of the other world. Riku is able to use the power of waking on the star to gain access to the world. The only known place in the other world is the city of Quadratum, the home of Yozora.

Worlds
A world (世界) is a location that appears in the Kingdom Hearts series. While the worlds were all connected in the ancient "age of fairy tales", they were split apart following the Keyblade War and exist independently. Each world follows its own flow of time.

In the context of the games, worlds are analogous to "levels" or "stages" that the protagonist must complete. They will explore the worlds and protect them from the Heartless, Nobodies, and other threats, often culminating in a boss battle against that world's villain or a denizen of darkness. Each world that appears in the Kingdom Hearts series is inspired by the films and cartoons they are based on. Oftentimes, the plot of the game in that world will be based on its original source as well.

World characteristics


There are over thirty worlds that have appeared in the Kingdom Hearts series so far. Most of them are based on 's animated features and contain locations and characters from or inspired by the films. As a result, worlds are greatly varied in appearance, style, and nature, as their sources range from the oldest cartoons in the Disney canon to modern Disney animations and live action Disney films. The oldest source is the 1928 cartoon ', used as a basis for Timeless River, while the most recent inspiration for a world from Disney's animated features is 2014's '.

In addition to the Disney-based worlds, numerous original settings were created by game developers as worlds unique to the Kingdom Hearts series. They tend to be populated by Square Enix characters from the, Disney characters without a world dedicated to their film, and original Kingdom Hearts characters.

Notes and references
Universum von Kingdom Hearts Verrou Céleste Tor