Universe of Kingdom Hearts

Concept and design

Nomura intended hearts, as well as the strengths and connections of the heart, to be a common theme in the games. Characters within the Kingdom Hearts series are composed of three parts: body, soul, and heart. The body acts as a vessel for the heart and soul, with the soul giving life to the body. The heart holds their memories, and gives them emotion, light, and darkness.

The Kingdom Hearts games are divided into various game levels, referred to as "worlds", which the player progresses through over the course of each game. Worlds vary in appearance, typically dependent on the Disney setting which they are based on. The worlds' graphics resemble the art style from the originating Disney film and the worlds are inhabited by characters from their respective films; for example, Hercules and Philoctetes appear in Olympus Coliseum from Hercules, while Aladdin, Princess Jasmine, and the Genie appear in Agrabah from Aladdin. The game worlds consist of interconnected field maps where battles and plot-related events occur. Players travel between worlds in different ways each game, such as the '"Gummi Ship'" in the original Kingdom Hearts, or via "keyblade glider" in Kingdom Hearts Birth by Sleep, by "Corridors of Darkness" in 358/2 Days, and "Sleeping Keyholes" as well as portals in Dream Drop Distance. Worlds created specifically for the series mirror the overall appearance of the other worlds and predominantly feature characters from Final Fantasy games and original characters.

Though Disney gave director Tetsuya Nomura freedom to choose which characters and worlds would be used in the games, he and his staff tried to stay within the established roles of characters and boundaries of the worlds. Nomura found managing and keeping consistent multiple worlds to be problematic. After determining the number of worlds in the universe, Nomura picked ones he felt would fit into the series' scenario. The list was then evaluated by his team and finally by Disney representatives. Nomura tried to maintain the same number of worlds in each game and made an effort to minimize any overlap in the overall look and feel of each world. He and his staff accomplished this by categorizing various Disney worlds by appearance and setting. For example, a world based on The Jungle Book was considered for the first game, but was omitted due to its similarity to Deep Jungle from Tarzan. They also tried to take into account worlds with Disney characters that would be interesting. For example, Nomura chose to include a Mulan world for its unique atmosphere. The Tron world's design was meant to emulate an old computer game in the style of the 1982 film. Nomura got the idea to include this world after seeing a Disney employee working on Tron 2.0. He hoped that the fact that it was so different from the other worlds would make it enjoyable to players.

Heartless

The Heartless are creatures born from the darkness of people's hearts, lacking a body or soul. Their name also references their total lack of positive emotions. They are the most common type of enemy the player encounters in the Kingdom Hearts series. When darkness consumes a character's heart, they become corrupted and turn into Heartless; a Nobody is created from the remaining body, which is considered to be the "empty shell" that the heart once inhabited, when the victim is of strong heart and will. Heartless act as forces of darkness, seeking to consume more hearts, including those of worlds. In addition, it still appears that people can "die" like normal if not transformed into a Heartless. Disney's Hades rules over the afterlife—or, more accurately, the underworld—where the deceased of various worlds seem to end up, including Auron from Final Fantasy X.′

Originally, the Heartless exist within an all-encompassing variety, the "Pureblood", who are usually ink-black in color. When defeated, they simply disappear in puffs of smoke. Before the events of the first Kingdom Hearts, these Purebloods are typically only encountered in the realm of darkness, although people with a strong will may summon them to the realm of light. While studying the Pureblood Heartless, as a side effect of their research to control the mind through the heart, Xehanort and Ansem's other apprentices devise the means to create artificial "Emblem" Heartless via the corruption of living hearts. They can be easily differentiated from the Purebloods with their more rich coloring and the Heartless insignia on their bodies. Unlike Purebloods, Emblem Heartless release hearts once defeated. However, unless the Keyblade is used to defeat the Heartless, the stolen hearts go to the realm of darkness where they turn into Heartless again. This combined with Maleficent's quest to gather the seven Princesses of Heart by using the forces of darkness have made the Heartless a common sight within the realm of light by the events of the first Kingdom Hearts.

Ordinarily, the Heartless are mindless and function on instinct, but obey those with strong will. However, in worlds closer to darkness, the Heartless are stronger and become uncontrollable. They invade worlds through corridors of darkness, which are unpredictable pathways that interlink the many worlds. The vast majority of Heartless that Sora encounters are Emblem Heartless.

Nobodies

When Heartless are created, the body and soul of those with strong hearts that have lost their hearts to darkness may become another type of creature called a Nobody. As they lack hearts possessing light and darkness, they are "nothing", yet still exist within the Kingdom Hearts universe. Despite this, the Nobodies do have the potential to gain new hearts of their own through time, separate from their original selves. Members of Organization XIII, a group of Nobodies central to the plot of the series, keep their human form because they possessed strong hearts as humans and thus remember their original existence. However, if they lack memories, such as weaker Nobodies, they assume malformed, inhuman shapes. Most members of the Organization control one type of Nobody suited to their fighting style.

Like the Emblem Heartless, the Nobodies have an insignia—an upside-down, incomplete heart—which was designed to look like a splintered heart as a complement to the Heartless emblem. Upon being defeated, a Nobody fades into a state of non-existence until its Heartless counterpart is destroyed with the captive heart released, recreating the original being they were splintered from.

Within the series, two Nobodies, Roxas and Naminé, are considered "special cases" regarding the circumstances of their births. Both are created when Sora uses Xehanort's Keyblade of Heart to release his and Kairi's hearts, respectively, but because of many peculiar events, manage to exist alongside (rather than in lieu of) their original selves. While many of Organization XIII's members resemble their original selves with their memories and personalities intact, Roxas resembles Ventus rather than Sora due to holding the former's heart within himself, and has none of Sora's memories. Meanwhile, Naminé, who has an even more exceptional circumstance due to being born of Kairi's heart but through Sora's body, in addition to not having Kairi's memories, has the ability to alter the memories of Sora and those close to him.

Unversed

The Unversed are creatures that appear in Kingdom Hearts Birth by Sleep, prior to the Heartless and Nobodies within the continuity. Described by Nomura as being "those who are not well-versed in their own existences", they are Vanitas' emotions given form, and feed on the negativity of others, which allows them to assume more powerful forms. Vanitas pits these creatures against his counterpart, Ventus, as a means of strengthening him as part of Master Xehanort's plan to obtain the χ-blade. Upon defeat, the Unversed's negativity reintegrates with Vanitas, allowing him to recreate them no matter how many times they are destroyed. The Unversed cease to be after Vanitas integrates back into Ventus and is subsequently destroyed within Ventus's subconscious.

Bugs

Kingdom Hearts Coded sees the inclusion of software bugs, simply referred to in-game as "'Bugs'", as the game's main antagonistic force. To investigate a message hidden in Jiminy Cricket's journal left by Naminé, King Mickey has the book digitized to uncover the mystery; however, due to the "hurt" the message contains, most of the data ended up corrupted, resulting in the data worlds being infected with bugs. They primarily take the form of Bug Blox which are cubes that the game's main protagonist, a virtual replica of Sora called "Data-Sora", can destroy or use as platforms. There are several different varieties of Bug Blox, the most common, breakable variety being black-and-red in color. Other bugs take the appearance of boss-level Heartless that Sora had defeated in Kingdom Hearts. Villains and boss-level Heartless make use of the bugs to assist them in fighting Data-Sora.

It is later learned that the recording of Sora's Heartless had gained sentience, and is responsible for the journal being blank even after the restoration of Sora's memories, due to how the book revolved around Sora; it seeks to devour the rest of the digital Heartless for power, and escape into the real world to sate its hunger for hearts. While its most basic form is the weak and common "Shadow" variety of Heartless, it grows increasingly powerful to the point where it takes other forms, such as an entirely black lookalike of Sora with yellow eyes, or a gargantuan variety of Heartless called "Darkside". The bugs cease to be after Data-Sora destroys the original bug and resets the entire datascape.

Dream Eaters

Dream Eaters are the main enemies of Kingdom Hearts 3D: Dream Drop Distance. Like the Heartless, they are created from darkness and are compelled to find the keyholes of worlds. In contrast to the Heartless, however, Dream Eaters originate from the darkness created in worlds that are in a state of "deep sleep" and are isolated from other worlds. Though Dream Eaters usually manifest as "Nightmares", creatures that devour good dreams and create bad ones, there are also "Spirits" that do the opposite by destroying Nightmares and leaving good dreams, and function as Sora and Riku's partners. Several boss enemy Nightmares appear under the control of Young Xehanort and various Disney villains throughout the game. Riku also temporarily turns into a Dream Eater himself by subconsciously entering Sora's dreams upon sensing Xehanort's interference with the Mark of Mastery exam.

Keyblades

Keyblades are key-shaped weapons created to combat darkness and are the only thing that can free hearts from a Heartless form, and destroy Nobodies, thus allowing the restoration of complete beings. Keyblades also have the ability to lock and unlock all manner of doors and keyholes. Originally, these Keyblades were crafted in the image of the original "χ-blade" by those who wanted the light within Kingdom Hearts for themselves, and those who sought the opposite. Wielders that are acknowledged as "Keyblade Masters" can bequeath the power to wield a Keyblade to one they deem worthy by letting them touch the handle of the blade (in Riku and Kairi's case) or connecting their heart to another (in Sora's case). There are also Keyblades like the one Xehanort uses that are passed down from different owners through generations.

A Keyblade changes in both appearance and strength with different keychains, which augment its wielder's fighting capabilities; some are obtained as a result of in-game events, while others can be obtained by completing mini-games. A driving element to the first game is the ability to seal the "heart" of a world by locking the keyhole to the door leading to it, preventing it from being destroyed by Heartless. In Kingdom Hearts II, the player uses the Keyblade to unlock pathways between worlds that were closed after the events of the first game. While Sora is the only one who uses the Keyblade in the first game, later games reveal more characters who wield Keyblades. In Birth by Sleep, Keyblades can be transformed into hovercrafts called Keyblade Gliders, which can be used to travel from world to world, making Keyblade wielders the only people with the means of transportation between worlds before Gummi Ships are used. The "gates" Sora would open later are known as the Lanes Between, which can be accessed by any Keyblade wielder.

χ-blade

The χ-blade, pronounced the same as "Keyblade," or as Xehanort mentioned once before "Kai-blade" (though you're more likely going to hear "keyblade"), is an ancient weapon of unknown origin introduced in Birth by Sleep that is capable of directly unlocking Kingdom Hearts. It is a double-handed weapon that takes the shape of two "Kingdom Key" Keyblades that intersect in an "X" shape, with additional features that give it the shape of an actual sword. The weapon has the power to open the heart of all worlds, and it exists alongside Kingdom Hearts as its guardian. It led to "Keyblades" being crafted in its image by those seeking Kingdom Hearts' power, those who sought to extinguish the light, and those who sought to protect it. The end result was the Keyblade War, which ended in a world known as the Keyblade Graveyard; the aftermath led the χ-blade itself to shatter into seven pieces of light and thirteen pieces darknesses. These seven lights, which are said to be the source of all light in the World, later became the hearts of the Princesses of Heart.

In Birth by Sleep, Master Xehanort's over-eagerness to obtain the weapon has him seek to clash two hearts of equal strength—one of pure light and one of pure darkness—with each other. He finds such a means through his former apprentice Ventus and the youth's personified darkness Vanitas, whom Xehanort created and enlisted to ensure his plans succeed. Though Ventus and Vanitas fuse back into one being with the χ-blade in hand, the reunion is not complete as the unstable χ-blade eventually explodes due to Vanitas' destruction within Ventus.

The events of Dream Drop Distance reveal that, as a contingency to his previous plan, Xehanort has arranged the formation of his thirteen "Seekers of Darkness", the new Organization XIII composing of his various incarnations and vessels, to fight the Keyblade users who would form seven "Guardians of Light", or target the Princesses of Heart, to recreate the χ-blade.

Kingdom Hearts

The titular "Kingdom Hearts" is the "heart of all worlds" and the source of hearts. It is an object of immense power and a central plot element that drives the conflict within the series as its light drove many to fight over it ages ago in what became the Keyblade War. In the end, Kingdom Hearts was consumed in the darkness caused from the conflict and the worlds became separate from each other. The return of Kingdom Hearts is sought by Master Xehanort during Birth by Sleep; while Kingdom Hearts does appear over the Keyblade Graveyard in the game, the flawed reunion of Ventus and Vanitas makes the unstable χ-blade explode, causing Kingdom Hearts to vanish. After splitting himself into a Heartless and a Nobody, Ansem (Xehanort's Heartless) seeks out the Door to Darkness to gain access to an artificial Kingdom Hearts he created from the hearts of worlds, while Xemnas (Xehanort's Nobody) seeks to create his own artificial Kingdom Hearts from the hearts of people. These artificial constructs however, are only small-scale versions of the "true" Kingdom Hearts, which can only be accessed with its counterpart, the χ-blade.

Each Kingdom Hearts takes different shapes depending on from which hearts they are created. The first game's Kingdom Hearts, artificially created from the hearts of worlds, has the appearance of a sphere of light beyond a white door. The Kingdom Hearts made by the Organization XIII, on the other hand, takes the form of a yellow heart-shaped moon. The true Kingdom Hearts called upon by the χ-Blade, as shown in Kingdom Hearts: Birth by Sleep, is a blue heart-shaped moon.

Worlds

The Kingdom Hearts universe is divided into planes of existence called "realms". Most of the series takes place in the "realm of light". Opposite the realm of light is the "realm of darkness", where Kingdom Hearts resides and where Heartless are born. The "in-between realm" is a plane where Nobodies come into existence. As well as these known realms, Ansem the Wise is banished to a "realm of nothingness", which he describes as a realm "where all existence has been disintegrated".

In the Kingdom Hearts universe, travel between worlds is normally not possible. Worlds are protected from extraterrestrial interference by an invisible shell. When the heart of a world is opened, the shell breaks apart, appearing as a meteor shower. Fragments from the wall are called "Gummi blocks" and can be used to make spaceships called "Gummi Ships", which serve as the main mode of travel between the various worlds. Gummi Ships can be shaped into any structure, and the origin of the Gummi Ship material allows for travel to other worlds. Gummi blocks can serve different functions, from navigation to offense and defense. Other methods to travel between worlds are the "corridors of darkness" and the "lanes between"—interdimensional pathways through which frequent travel eventually erodes the user's heart with darkness. These pathways are normally used by Heartless and Nobodies, but have been used by other characters in the series, including Riku and Mickey Mouse.

Those who travel between worlds are advised to limit their interactions with the inhabitants of foreign worlds in order to maintain the world order. For this reason, the main characters change their appearance in certain worlds to avoid standing out. In the worlds based on The Little Mermaid and The Nightmare Before Christmas, Sora, Donald, and Goofy transform into undersea creatures and Halloween monsters, respectively. For The Lion King, they transformed into animals (or, in Donald and Goofy's case, less humanoid forms) because Nomura felt that it would appear odd to have Sora and the others interact in their standard forms, since no humans appear in that film.

Disney worlds

The majority of worlds that appear in the games are based on Disney films. Most of these worlds, such as Wonderland, the Land of Dragons, and Deep Jungle, follow abridged versions of the stories found in their respective films. Agrabah notably covers the first two Aladdin films in Kingdom Hearts and Kingdom Hearts II, while Atlantica and Halloween Town only mirrors its films in the second game, having an unrelated plot in the first game. On the other hand, worlds like Monstro and Neverland focus heavily on the main Kingdom Hearts plot, the latter being reduced to Captain Hook's ship, where Riku reveals to Sora that Kairi has lost her heart; these worlds would not be able to be explored in full until the later releases of Kingdom Hearts 3D: Dream Drop Distance and Kingdom Hearts 358/2 Days, respectively. In the case of Beauty and the Beast, the Beast appears in Kingdom Hearts to aid Sora when he temporarily loses the Keyblade. After Beast's Castle is restored at the end of that game, the Beast becomes a pawn in the plot of Organization XIII during Kingdom Hearts II.

During the development of Kingdom Hearts II, Nomura had more creative freedom due to advances in technology. Port Royal, Space Paranoids, and Pride Lands, in particular, benefited from these advances. In Port Royal and Space Paranoids, the character models were generated from live-action pictures using a new program. Nomura had wanted to include a world based on The Lion King in the first game, but could not since its engine could not process quadrupedal character models properly, a feature which was resolved for Kingdom Hearts II. A sub-world of Disney Castle is Timeless River, meant to be the "past" of Disney Castle, shortly before it was built. The world is portrayed in black and white; Nomura had intended it to be this way from the beginning of development. The world has many throwback effects including intentionally poor sound quality to imitate old cartoons. In this grayscale world, Sora's character model is simplified to the style of early cartoons, while Goofy and Donald Duck revert to their original designs from when they first appeared in Disney cartoons.

Birth by Sleep introduced several new Disney-based worlds to the series: Castle of Dreams, Enchanted Dominion, Dwarf Woodlands from Snow White and the Seven Dwarfs and Deep Space. Dream Drop Distance included more new Disney worlds, such as La Cité des Cloches, The Grid, Prankster's Paradise, Country of the Musketeers, and Symphony of Sorcery.

Kingdom Hearts III will introduce more worlds such as Kingdom of Corona and one based on Big Hero 6. When questioned on the possibility of including worlds based on Disney-purchased properties such as Pixar, Marvel Entertainment and Lucasfilm, co-director Tai Yasue said, "We have to come up with a world that has a lot of originality. We want variety... so we don't want too many of one sort of world, that would look the same. For each world there has to be some meaning for it, in the plot... Also, gameplay-wise, is that world something that would make gameplay fun?" The game will not feature any worlds based on Final Fantasy.

In addition to the Gummi Ship minigame, minigames feature prominently in certain worlds. All appearances of the 100 Acre Wood consist entirely of minigames based on classic Winnie the Pooh shorts, with Sora taking on the role of Christopher Robin. Olympus Coliseum features optional fighting tournaments; due to Hades' popularity, the Underworld was added in Kingdom Hearts II, where Hades has opened his own tournament. While Atlantica is a normal world in Kingdom Hearts, albeit with a special "underwater" control scheme, it becomes an interactive rhythm game in Kingdom Hearts II which is completely unrelated to the overall story and serves as mere filler. Finally, Space Paranoids features a Light Cycle mini-game that strongly deviates from the original film. Nomura included this minigame because he knew people associated the Light Cycles with Tron.

Original worlds

The worlds created specifically for the series predominantly feature original and Final Fantasy characters and figure more centrally to the overarching plot of the Kingdom Hearts series. The first world of each game serves as a tutorial to introduce new gameplay elements and frame the story. Destiny Islands, the home world of the main characters, Sora, Riku, and Kairi, serves this function at the beginning of the first game and Kingdom Hearts Re:Coded. The next available world serves as a hub world, where the player returns multiple times throughout the game to unfold the main story. Traverse Town, a world cobbled together from the remains of worlds destroyed by the Heartless, fills this role in Kingdom Hearts, but becomes the tutorial world in Kingdom Hearts: Chain of Memories. The penultimate world of each game wraps up many plot threads in preparation for the final world. Hollow Bastion is this world for Kingdom Hearts, but in Kingdom Hearts II, it is the hub world. Twilight Town is both the tutorial world and the penultimate world in Kingdom Hearts II, containing a secret pathway to the final world of that game. The final world culminates in a battle with the main antagonist of the game. The "End of the World", made out of the worlds that lost their hearts to the Heartless, and the "World That Never Was" are the final worlds of Kingdom Hearts and Kingdom Hearts II, respectively. In Kingdom Hearts Birth by Sleep, the Land of Departure serves as the tutorial world, while the final world in the game is the Keyblade Graveyard, where each of the main characters' final battles take place prior to the game's final episode.

Hollow Bastion plays a central role in the backstory of the series, as the home world of a majority of the Final Fantasy characters who appear in Kingdom Hearts, as well as the original home of Ansem the Wise, the ruler of that world, then called the Radiant Garden, and Kairi, who was sent to the Destiny Islands as part of an experiment conducted by Ansem's apprentice, Xehanort. Ansem studied the darkness in people's hearts with Xehanort and five other apprentices, who continued this dangerous research without his permission, causing the world to become overrun by darkness. Deserted, the castle was later adopted by Maleficent as a headquarters. Castle Oblivion, another villainous hideout and the main setting of Kingdom Hearts: Chain of Memories, consists of multiple floors which transform into memory-based reconstructions of other worlds, via special cards. Finally, Organization XIII is based in the World That Never Was, a world in the in-between realm that houses Kingdom Hearts. This conception of Kingdom Hearts was designed to appear as the heart-shaped moon from the cover of the first Kingdom Hearts game. When the scenario writer, Kazushige Nojima, created the scenario, he described it as a moon floating in the World That Never Was. Upon reading that, Nomura thought of using the visuals from the first game to create a connection.

Reception

The series' setting has garnered a mixed to positive reception from critics. Following Kingdom Hearts's initial announcement, publications expressed skepticism towards the first game's viability. Andrew Reiner of Game Informer stated that despite the extreme differences between Final Fantasy and Disney properties, they blend well together along with the new content created for the series. A second Game Informer reviewer, Matt Miller, described the concept as a "hard sell", describing the combination of the two properties as "ridiculous". Though in contrast, he stated the franchise's formula is successful. The graphics of the games have received generous praise, with particular focus on their similarity to the source material. IGN stated that the "worlds look very much like their filmed counterparts". Japanese gaming site, Gpara.com also praised the look of the worlds. GameSpot referred to the worlds as "wonderfully rich familiar environments", and GamePro described the worlds as "spot-on with the original movies."

Following the release of the first game, the Disney settings were well received by critics. Allgame's Scott Marriott stated the Disney settings are the most attractive feature of the game and considered some of the world choices a surprise. He praised the level designs, commenting that a good amount of familiar elements from the Disney films were integrated into them. Marriott further stated that though the stages were small, interacting with beloved characters and exploring familiar settings were enjoyable aspects. Maura Sutton of Computer and Video Games attributed the Disney elements as a major factor in creating the game's "astounding worlds". She summarized her review by calling Kingdom Hearts a "delightful mixture of two enchanted worlds". Video game critics of Kingdom Hearts: Chain of Memories expressed disappointment at the limited number of new worlds to explore in the game. 1UP.com's Bryan Intihar lauded Kingdom Hearts II's environment, calling it appealing and stating it was an improvement over the first title's. He described the level designs as "impeccable", citing the presentation of Timeless River stage's atmosphere. Intihar further commented that the expansions and changes to previous worlds made them "feel fresh". In contrast, Reiner described the Disney elements in Kingdom Hearts II as "tacked on".