Universe of Kingdom Hearts

In the Universe of Kingdom Hearts there are many worlds that fall into certain realms. All of these realms are on their own plane of existence. Other than the Realm of Nothingness, the planes are parallel to each other.

Plane
A Plane or Plane of Existence is a flat surface with infinite width and length. There are only two planes in Kingdom Hearts. These planes have been dubbed with the names of the Realm of Light and the Realm of Darkness. The worlds that are visited in Kingdom Hearts belong to one of the two planes with the exception of Traverse Town, Castle Oblivion, Twilight Town, Mysterious Tower, The World That Never Was, and the Land of Departure, which exists between these two planes in the Realm of In Between.

The Realm of Light contains all the 'normal' worlds such as Destiny Islands, Deep Jungle, and Halloween Town. The Realm of Darkness is only known to contain Kingdom Hearts. It can be conjectured that the Realm of Nothingness takes place outside of the planes and not in the between area. These planes or realms should not be confused with worlds, however traveling from plane to plane or to the places in between the planes can be done via Gummi Ship, Corridor of Darkness, and even stairs just like worlds. Traveling between planes can also be done via Doors, such as the Door To Light and the Door To Darkness. The planes as well as the areas outside are a part of the Sea of Outer Space.

Stairs were only mentioned once by Tetsuya Nomura's in the Director's Secret Report XIII. Tetsuya Nomura's stated that to fully imagine the Kingdom Hearts universe correctly "you can imagine two planes with stairs ranging between the worlds (on the planes)".

Realm of Light
The Realm of Light (光の世界) is a realm made up mostly of light and makes up almost half of the Kingdom Hearts universe, similar to the Realm of Darkness. Like the Realm of Darkness, the Realm of Light has a Keyblade, notably the Kingdom Key, which chose Sora as its wielder. Most of the game's worlds are found here, save for those in the Realm of In Between, like Twilight Town, Castle Oblivion, and The World That Never Was. It can be presumed that most of the Worlds accessible by the Gummi Ship are either within the Realm of Light, or are related to it, like Twilight Town.

In Kingdom Hearts II, one notable citation has been made by Sora regarding the Realm of Light during the scene of Sora and Riku at the "end of the road" after defeating Xemnas: ''The other side... The realm of light is safe now. Kairi, the King and the others are there.''

The door leading to the Realm of Light is called the Door to Light. It was the door Sora and Riku went through while they were stuck in the Realm of Darkness. It is not sure what caused the door to appear, one reason could be, as Riku pointed out at the end of the game, was the light within Sora's Heart which was brought out by Kairi's Letter.

It's opposite counterpart is the Door To Darkness.

Realm of Darkness
The Realm of Darkness (闇の世界) is a realm made up of Darkness in people in every world. As with the Realm of Light, this realm has a Keyblade which chose King Mickey as its wielder. Kingdom Hearts is found here. This is also the home of all the Heartless, as this is where the most powerful ones can be found. Sora fought Xehanort's Heartless here in Kingdom Hearts.

Sora, Donald, and Goofy visit the Realm of Darkness after being saved from Saïx by Maleficent in Hollow Bastion, where they encounter a man in a black coat, later revealed to be Riku. Riku leaves a box with a picture of Hayner, Pence, Olette, and Roxas and a bar of sea-salt ice cream. In this same realm, the Keyblade reacts to the ice-cream and Sora opens a pathway. This is the first time that Sora, Donald, and Goofy are able to make their way to the Realm of Darkness in Kingdom Hearts II.

It is interesting to note that, before Xehanort and the other five began their meddling, only Pureblood Heartless existed, as well as the fact that the Heartless could only be summoned into the Realm of Light, not being able to do so at will with a corridor of darkness. It would seem, therefore, that not only did Xehanort invent an entirely new breed of Heartless, but also inadvertently broke down a significant barrier between the two realms. This could explain what Ansem meant when he was talking about the Realm of Light being in danger in the secret ending of Kingdom Hearts Birth by Sleep.

Time moves more slowly in the Realm of Darkness than in the Realm of Light.

Corridor of Darkness
Corridors of Darkness are unpredictable pathways that interlink the worlds of the Kingdom Hearts universe. The Heartless use these extensively to reach other worlds, as do members of Organization XIII, their subordinate Nobodies, and many other characters. These pathways are formed out of Darkness, so it is unsafe for a normal person to travel them, because the constant use of these corridors would corrupt one's heart. However, the Heartless and the Nobodies don't have to worry about this, since the Heartless already have corrupted hearts, and the Nobodies do not have hearts to corrupt. However, one upside to this is that it provides a faster means of travel than the Gummi Ships.

Other characters who have used these corridors include King Mickey, Kairi, Riku, Naminé, DiZ and even Pluto. Of these, only Riku, Naminé and DiZ have been responsible for summoning the portals, and only those lacking hearts to corrupt (Nobodies), and those who are darkness (Heartless) aren't affected, with two noted exceptions; According to Nomura in the Director's Secret Report XIII, Riku and Mickey aren't affected by darkness at all, due to some "secret similarities". Ironically, in the first Kingdom Hearts, after the face-off in Neverland, Riku's heart was significantly weakened as he carelessly used a Corridor of Darkness to return to Hollow Bastion. Nomura goes further to state that DiZ and the Beast can successfully use the Corridors of Darkness, and perhaps open them, due to their particularly strong feelings. Furthermore, despite Sora having used the Corridors of Darkness several times before, he has not used them frequently enough to allow the Darkness to stain his heart. The influential power of Darkness depends on the strength of a person's heart.

Anyone who has traveled in darkness for too long would show a few physical traits: their skin darkens and their eyes turn amber. This is especially true for Xehanort, whose Heartless and Nobody both have tan skin and amber eyes. In the case of Ansem the Wise, it is not so severe: he only has amber eyes.

Maleficent is also believed to travel the Corridors, though she does not show the physical changes. This could be due to her trying to command the Darkness, instead of becoming one with it. It is also know that Pete travels the Corridors as well. He is known to be protected from the Darkness by Maleficent's magic.

The black coats worn by Riku, King Mickey, and Organization XIII are said to protect wearers from the effects of darkness, and from detection by those who use darkness. Thus, those who wear these coats can traverse Corridors of Darkness without suffering the negative effects.

Dark Margin
The Dark Margin (referred to by Tetsuya Nomura as the Dark Coastline) is a mysterious place in Kingdom Hearts. It is first seen in "Another Side, Another Story" (Deep Dive) video.

In Kingdom Hearts II and In Kingdom Hearts 358/2 Days, Roxas converses with Xemnas at the Dark Margin. He talks to Roxas, telling him how much he looks like Sora.

It reappears in the end of Kingdom Hearts II. After defeating Xemnas, Riku and Sora end up on the Dark Margin. Suddenly, after Sora reads a letter from Kairi, a door appears leading them to Destiny Islands.

According to Another Report, Nomura states that the Dark Margin is "the tip of a world", i.e. the boundary between Darkness and In Between. Sora and Riku were on the coast of the side of In Between, and were looking over the sea in the Realm of Darkness. Having said thus, the Door to Light which appeared in the ending scene is reminiscent of a quote which recurs in the Kingdom Hearts series, albeit in different words: "No matter how deep the Darkness, a light shines within."

Blank Points
In Kingdom Hearts Birth by Sleep's secret event, Aqua finds Ansem the Wise sitting on the coast of the side of darkness. The scene takes place some time after the machine Ansem used to encode Kingdom Hearts as data exploded in Kingdom Hearts II. Instead of killing him, the machine's explosion transported Ansem to the dark realm and caused Ansem to slowly lose his memory (he likely made his way there after Sora and Riku left). Aqua and Ansem the Wise have a conversation about the worlds and how Ansem came to know Sora. This leads Aqua to shed tears of hope and say Sora's name, knowing that he would save her and her friends.

Realm of In Between
The Realm of In Between (or the Realm of Twilight) is the third realm in the Kingdom Hearts series, and lies between the Realm of Light and Realm of Darkness.

Thus far the only known Worlds to exist in this plane are: Traverse Town, Castle Oblivion, Twilight Town and The World that Never Was. 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. The Mysterious Tower also exists in this Realm.

Realm of Nothingness
The Realm of Nothingness is the fourth realm in the Kingdom Hearts universe. Nothing exists here and if one stays in there for too long, they will cease to exist. The only way to survive here is to remember your past.

After being banished from Hollow Bastion by Xehanort, and his apprentices, Ansem the Wise wandered into the Realm of Nothingness and coined a new name for himself, DiZ. As DiZ, he managed to survive in the Realm by exercising his mind, via writing his Reports, and clinging onto his hatred of Xehanort.

Sora and Riku briefly entered the Realm of Nothingness during their final battle with Xemnas.

Worlds
A World (世界) is a location that appears in the Kingdom Hearts series. Serving as the "levels" for the games, Sora and other characters are charged with visiting and protecting them through the course of the series. By defending the worlds from the Heartless, Nobodies, or other enemies, Sora keeps the Darkness from spreading and the worlds from being manipulated or destroyed. At the end of every world Sora, Donald, and Goofy have to fight a giant Heartless Boss which opens the Keyhole area when defeated. At the end Sora locks the Keyhole and earns a Gummi that will let him go to the next world.

Each world that appears in the Kingdom Hearts series has its own distinct look, and for the most part hold true to the movies and cartoons they are based off of. Often the plot of the game in that world will be based on its original source. Almost all worlds can be visited in the course of the game and are part of the playthrough; there are exceptions, though, since some places can be seen in cinematics but not actually accessed by Sora's party.

World characteristics
There are over thirty worlds that have appeared in the Kingdom Hearts series so far. Most of them are based on Disney'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 created by Disney to more current movies in the Disney canon. The oldest source is the 1928 cartoon "Steamboat Willie", used as a basis for Timeless River, while the most recent inspiration for a world from Disney's animated features is 2002's Lilo & Stitch, the source for Deep Space. In Kingdom Hearts II, two live-action films, Pirates of the Caribbean: The Curse of the Black Pearl and Tron served as the foundation for the worlds Port Royal and Space Paranoids.

In addition to the Disney-based worlds, eleven worlds are exclusives that were created by game developers Square-Enix just for the Kingdom Hearts series. They are not part of the Disney film canon, nor Square-Enix's games canon, but do tend to be populated with Square-Enix characters, especially from the Final Fantasy series, as well as the occasional Disney character or original characters created just for Kingdom Hearts.

Some worlds have names that don't seem to accurately reflect what is found there. A famous example is Neverland in Kingdom Hearts; Sora and company get to go through Captain Hook's ship and fly around the Clock Tower, but never actually reach the island Neverland where Peter Pan and Tinker Bell live. To further confuse things, some worlds in Kingdom Hearts II contain what could almost be considered sublevels or second worlds within them, such as the Underworld at Olympus Coliseum or Christmas Town in Halloween Town.

Kingdom Hearts Birth by Sleep
Kingdom Hearts Birth by Sleep does not feature set party members and only allows a solo party for most of the game, except for a handful of battles, in which one or two additional members are assigned to your party. However, the game features a system called Dimension Link in which the character controlled can tap into the power of their friends across worlds and thus gain unique commands and abilities.
 * Land of Departure's party members are Terra, Aqua, and Ventus
 * Deep Space's party member and D-Link is Experiment 626
 * Neverland's D-Link is Peter Pan.
 * Enchanted Dominion's party member is Prince Phillip, and its D-Link is Maleficent
 * Radiant Garden's party members are Terra, Aqua, Ventus, and King Mickey
 * Olympus Coliseum's D-Links are Zack and Hercules
 * Keyblade Graveyard's party member is King Mickey

Kingdom Hearts
In certain worlds, a character from that area will be available to fight, and can replace Donald or Goofy in the party. Kingdom Hearts had six such worlds with party members.


 * Deep Jungle's party member is Tarzan.
 * Agrabah's party member is Aladdin.
 * Halloween Town's party member is Jack Skellington.
 * Atlantica's party member is Ariel.
 * Neverland's party member is Peter Pan.
 * Hollow Bastion's party member is Beast.

Kingdom Hearts II
Kingdom Hearts II increased the number of worlds with party characters to nine, putting a party member in almost every Disney-based world. Three characters from Kingdom Hearts returned for battle: Aladdin, Jack Skellington, and Beast, although Beast was moved from Hollow Bastion to his own world. Ariel reappeared in Atlantica, but no longer as a party character, Peter Pan became a Summon, and Simba, formerly a Summon, became a party member in his home world of Pride Rock. The game added two party members with the same first name as another; Jack Skellington and Jack Sparrow; Sora differentiates between the two by referring to Jack Sparrow as Captain. To make the world-based party members more powerful, special attacks were developed for each character that Sora could call on in the heat of battle. Kingdom Hearts II also included the first Final Fantasy party character, Auron, and allowed Sora to fight alongside his best friend, Riku.


 * The Land of Dragons' party member is Mulan.
 * Beast's Castle's party member is Beast.
 * Olympus Coliseum's party member is Auron.
 * Port Royal's party member is Jack Sparrow.
 * Agrabah's party member is Aladdin.
 * Halloween Town's party member is Jack Skellington.
 * Pride Lands' party member is Simba.
 * Space Paranoids' party member is Tron.
 * The World That Never Was' party member is Riku.

Kingdom Hearts coded
The worlds in Kingdom Hearts coded are the same as the first game but the party members are different.


 * Olympus Coliseum's party members are Hercules and Cloud.
 * Agrabah's party member is Genie.
 * Hollow Bastion's party members are Donald and Goofy.

Star
Stars are massive, luminous balls of plasma that are held together by their own gravity.

In the Kingdom Hearts games, each star is the fragment of one specific world. Should a star stop shining, that would mean that particular world has disappeared from existence, most likely from destruction from the Heartless.

In Kingdom Hearts, many stars disappeared. In Mickey's letter to Donald (before Destiny Islands is attacked by the Heartless), Mickey mentions the fact that the stars have been disappearing, one by one, and so he went to find out why. When Donald and Goofy first arrived at Traverse Town, they discovered a star corresponding Destiny Islands fade out of existence. They were restored after Sora and his friends stopped Ansem's plan to plunge the world into darkness.

Travel
Travel between the worlds is normally impossible. The worlds are all protected by dimensional barriers that prevent outsiders from entering for the most part. However, these barriers can be broken, resulting in a meteor shower in that world.

In Kingdom Hearts and Kingdom Hearts II, Sora, Donald, and Goofy use the Gummi Ship to travel between worlds on the World Map, an event that serves as a mini-game between areas. Some worlds require certain special Gummi Blocks to access; for example, a special Navigation Gummi must be installed by Cid to unlock a second set of worlds in Kingdom Hearts. Once they reach them, the party can enter and then depart each world through its Save Points.

Three worlds can only be accessed by entering through other worlds and do not directly require use of a Gummi Ship:
 * 100 Acre Wood via Pooh's book in Traverse Town (Kingdom Hearts) and Hollow Bastion (Kingdom Hearts II).
 * Timeless River via the Hall of the Cornerstone at Disney Castle.
 * Space Paranoids via Ansem's computer in Hollow Bastion.

It should be noted that in Kingdom Hearts: Chain of Memories, there are no Gummi Ships; the worlds Sora visits are recreations from his memories from the first game brought to life on each floor of Castle Oblivion.

There are five known ways to travel through the worlds:
 * Piloting a Gummi Ship; as Gummi Ships are composed of fragments of shattered barriers, they are capable of passing through them.
 * Utilizing the Corridors of Darkness; this is a faster means of travel than the Gummi Ships, but those who use them are at great risk of being corrupted or destroyed by the darkness.
 * Teleportation; Merlin was able to teleport himself, Sora, Donald, and Goofy from Hollow Bastion to Disney Castle.
 * A Gummi Block called "Star Fragment" that Master Yen Sid gave Mickey to travel across worlds during Kingdom Hearts Birth by Sleep.
 * Keyblade Ride; Terra, Aqua, and Ventus can change into their armored form and turn their Keyblades into vehicles that can travel to other worlds.

History
According to the story told by Kairi's grandmother in the Hollow Bastion's Library, long ago there was one single world, that was constantly bathed in the warmth of Light. When people began to fight over the Light within their world, Darkness appeared in their hearts, and the world was consumed. However, fragments of light remained within the hearts of children. From this light, children were able to rebuild the lost world. But darkness still existed, that's why the worlds are separate from each other, divided, waiting for the true light to return. This was expanded on in Birth by Sleep, where it was revealed the fight was between the many Keyblade holders over Kingdom Hearts, and eventually led to the Keyblade War.

Prior to Kingdom Hearts, the worlds were surrounded by barriers, to prevent outside interference, making it impossible for different worlds to have contact. The arrival of the Heartless caused the barriers between the worlds to crumble and disappear, and some worlds were even consumed by the Heartless. Gummi Blocks are actually pieces of these broken barriers. The metaphysics of this prior to Kingdom Hearts is unknown, but will probably be revealed in Kingdom Hearts Birth by Sleep.

Those who travel between worlds are advised to limit their interactions with the inhabitants of foreign worlds, and their meddling in the affairs of those worlds, in order to maintain a balance of separation. To this end, several characters, notably Sora, Donald, and Goofy, magically alter their physical appearances in certain worlds to avoid standing out. For example, they become sea creatures in Atlantica, Halloween monsters in Halloween Town, jungle animals in the Pride Lands, and computer A.I.s in Space Paranoids.