In the world of Kingdom Hearts, not restricted to just people and animals, but every existence contains a heart. The collection of all kinds of hearts would become the great heart – Kingdom Hearts.
Heart of Worlds and Key Holes
The worlds contained in the Realm of Light all consist of a Heart of the World. A Heart of the World is essentially the collection of hearts that make up everything in that world, and there is always a Key Hole hidden deep within each world.
The Key Hole to the Heart of Worlds is also connected to the Realm of Darkness. Generally the Key Holes are closed and on one hand the worlds are protected from darkness, but at the same time there is no path to get outside the world. If the Key Hole is opened, the barrier surrounding the world is destroyed so that entering and leaving the world becomes possible, but this also allows the darkness to seep into the world, so it can be extremely dangerous. In KH1 the Hearts of Worlds are open leaving them volatile, so Sora and his friends go on a quest to lock the Key Holes.
The Key Hole to a Hearts of the World is hidden from sight, but when a Keyblade is held up it will appear.
Because Riku received the Keyblade Inheritance Ceremony as a child, he was able to see Key Holes others could not.
The Key Holes Locked and Unlocked
Aside from the Key Hole to the Heart of the World, there are various other Key Holes. In all other adventures aside from KH1, Keyblades were used to open Key Holes on various worlds, including those that were not the Key Holes to the Heart of the Worlds.
How the Protagonists Interacted with Key Holes
KH1 – Sora – To stop the darkness from entering worlds, he traveled between worlds in the Gummi Ship to close off the Hearts of Worlds.
KH2 – Sora – With the intention of helping reclaim worlds, he had to open gates made by the worlds to travel between them.
KH coded – Data Sora – In attempts to restore the data in Jiminy’s journal, he traveled through Data Worlds and opened their Key Holes in order to get rid of the bugs.
KH BbS – Terra, Aqua, Ventus – They opened the Key Holes leading into the corridors of space which Eraqus readied in order to travel between worlds.
KH3D – Sora, Riku – Challenging the Mark of Mastery, they traveled between Sleeping Worlds opening their Key Holes in order to free them from dreams.
Aside from KH1 where Sora closed Key Holes, all the other installments involve opening Key Holes.
A condensed form of the hearts of this world. Also known as the kingdom of hearts or the center of worlds. It also is the source of great power and a source of endless knowledge.
In the past, people viewed Kingdom Hearts as a great heart of light and seeking to gain control of this ended up causing the outbreak of a war that destroyed the world (Refer to P.8). Because of such an incident, Kingdom Hearts is now strictly sealed away and it is not easily approachable. Master Xehanort among other dark forces use all kinds of tactics to obtain Kingdom Hearts, but Sora is always there to fight and stop them.
Kingdom Hearts of Worlds (KH1 Kingdom Hearts)
The condensed form of the Hearts of Worlds known as Kingdom Hearts. The path to this Kingdom Hearts can only be open using the Keyblade of People’s Hearts created from the Seven Princesses of Heart. In KH1, Maleficent and Ansem used the Heartless to steal the Hearts of Worlds and sought out the Kingdom Hearts of Worlds.
Kingdom Hearts of People (KH2, 3D Kingdom Hearts)
The condensed form of the hearts of people becoming a Kingdom Hearts. Organization XIII believed that completing this would make them whole again and began collecting hearts from the Heartless in order to create the Kingdom Hearts of People. The leader of Organization XIII had a different plan as he intended on using the Kingdom Hearts of People in order to implant the heart of Xehanort into the members as vessels to create the 13 of Dark (Reference P.9).
The incomplete Kingdom Hearts of People floated above Organization XIII’s castle.
True Kingdom Hearts (BbS, 3D Kingdom Hearts)
Different from the two man-made Kingdom Hearts above, this Kingdom Hearts has existed since the beginning of the world. It was engulfed in darkness long, long ago during the Keyblade War, but using its counterpart: the χ-Blade, it is thought that the True Kingdom Hearts will once again be revealed.
Master Xehanort’s goal is to acquire the χ-Blade and open the True Kingdom Hearts to bring about a new Keyblade War.
The Door of Darkness and the Door of Light
The door leading to Kingdom Hearts is also the Door of Darkness connected to the Realm of Darkness. Only those shrouded in darkness may pass through the Door of Darkness, and to seal this door, a Keyblade from the Realm of Light and a Keyblade from the Realm of Darkness are both necessary. One must be in the Dark Realm and the other in the Light Realm in order to combine their powers and lock the door from both sides.
The counterpart for the Door of Darkness is the Door of Light. This door is how someone belonging in the Realm of Light who is lost in the Realm of Darkness may return to the Realm of Light and it will appear as if it were inside a person’s heart.
King Mickey uses the Keyblade he obtained in the Realm of Darkness to work with Sora in the Realm of Light to seal the Door of Darkness.
When Sora and Riku were lost in the Realm of Darkness, they found hope in a letter they received from Kairi and were then able to find the Door of Light.
7 women who all hold a pure heart of light without darkness and their very existences are the foundations for light. They are sought out by dark forces as their hearts can reveal the path to Kingdom Hearts.
The Seven Princesses are Bell, Snow White, Aurora, Alice, Jasmine, Cinderella and Kairi.
Despite all the princesses living in different worlds, the Villains (Refer to P.9) were able to kidnap all of them and use their pure hearts to create the Keyblade of People’s Hearts.