Set directly after the events of Kingdom Hearts II, Kingdom Hearts coded is in deep connection with the up-and-coming prequel Kingdom Hearts Birth by Sleep. It follows the story of the mystery behind the missing contents of the journal – logged by the chronicler of Sora, Donald and Goofy’s adventures, Jiminy Cricket – of Kingdom Hearts. The hero is Data Sora from the journal who is asked by King Mickey to help solve the puzzle behind one of two remaining lines: “We must return to free them from their torment”. However, there is another problem: black and red blocks known as “Bugs” are appearing in the worlds of the journal, preventing Sora from unveiling the mystery, and causing trouble in both the outside world and the journal itself. While Sora fights for the truth, there are certain dark forces whose agenda is nothing but malicious and will do anything to stop him from completing his task. With a series of unexpected twists and turns, Kingdom Hearts codedwill uncover the shocking truth of the events of Kingdom Hearts.

The story begins with Jiminy returning to Disney Castle with Mickey, Donald and Goofy, and discovering that the journal in which he recorded the events ofKingdom Hearts has been wiped clean of its contents apart from two lines: “Thank Naminé” and “We must return to free them from their torment”. While the first message suggests that a duty of Kingdom Hearts must have been completed, the second message indicates otherwise. Unable to remember the text, Jiminy shows the message to Mickey.

The King also has problems understanding it, but tries to digitize the journal to better understand the problem; as soon as he does, red and black blocks fill the view; something is happening to worlds inside. Knowing that there is only one person qualified to solve the puzzle of the journal and the blocks, he asks Data Sora to embark upon a mission that will take him through the worlds that the real Sora has visited, and so the adventure begins.

Data Sora awakens in the familiar Destati – which the real Sora experienced at the beginning of Kingdom Hearts –; it is the beginning of his journey guided by Mickey from the outside. He is told that power sleeps within and after choosing a weapon, he gains the ability to traverse worlds freely. However, problems arise inside Destati and the outside world – a hooded figure appears from thin air, and a new message appears in the journal. Are the two related? The figure is silent and then disappears, and Mickey orders Sora to follow him. When he does, he is swarmed by Heartless but fortunately the Keyblade comes to the rescue and Sora ends his Destati, moving to his next destination.

Destiny Islands is just one of the worlds which is covered in Bugs, with rumors and actual sightings of the cloaked figure. All the time, new messages are appearing in the journal, throwing this seemingly simple task of destroying the Bugs and unveiling the mystery into a whole new level of hidden truth. Everything is not as it seems as the real and journal worlds intertwine, and danger is more prominent than ever with old enemies once again trying to throw the worlds into darkness. Questions are asked, truths are uncovered and even more mysteries present themselves. What are the Bugs and why are they contaminating the worlds? Who is the hooded figure and what does he want? Who must Sora free from torment? The truth to the secrets of Kingdom Hearts lies on one boy’s shoulders, and if he should fail to complete his task, everything will be thrown into turmoil.

Kingdom Hearts coded is set after Kingdom Hearts II, but set in the journal of Kingdom Hearts—a journal which has been erased by an unknown force. It is the journey of Data Sora – a digitized version of the real Sora – who embarks upon a quest to find the meaning behind a mysterious message left in the journal: “We must return to free them from their torment.” His travels are guided and aided by friends of the real Sora – including the King and his consorts and one of Sora’s best friends, Riku – as he voyages through the worlds of Kingdom Hearts, destroying mysterious “Bugs” which are causing corruption in the notebook world. Little does Data Sora know that the events which are unfolding around him are in deep connection with events of ten years ago that took place during Kingdom Hearts Birth by Sleep; now, everything lies on his shoulders, and if he fails, so help the data world and all of its inhabitants.

The adventure’s catalyst comes in the form of the only remaining line left in Jiminy’s journal—“We must return to free them from their torment.” While it is Mickey who takes action to discover its meaning and why it is the only thing inked in the notebook, the hero of action is Data Sora. Unbeknownst to Mickey – who decides to send the virtual Sora through the worlds visited in Kingdom Hearts – it is this line that is deeply linked with the events of Birth by Sleep.

The worlds Sora visits are covered by “Bugs”—the corruption in the journal given physical form, which are the result of Naminé’s efforts to restore the real Sora’s memories as seen in Kingdom Hearts Chain of Memories. It would appear that while she was fixing his memories, the memories of someone else connected to him caused a kink in the chain, bringing about the journal’s Bugs and message. Though finding the source of the Bugs is a large part of Data Sora’s travels, far bigger and more dangerous secrets are to be uncovered.

One of these is the identities of two Hooded Unknowns following Sora, one of whom is none other than real Sora’s best friend’s virtual counterpart, Data Riku. This Riku follows Sora through the first few worlds of the journal, encouraging Sora to keep on fighting, before he eventually reveals himself; however, this Riku has a twist to his story—he is actually hosting the journal’s scattered memories so that they wouldn’t be corrupted by the Bugs which is important for the fixing and reassembling of the journal’s data. After his identity is uncovered, Riku helps Sora through the rest of his journey along with the King and company.

Sora’s journey is relatively smooth as he follows a seemingly straightforward pattern that consists of visiting worlds, destroying their Bugs and restoring world order. However, the data world and the real world soon become intertwined due to the meddling of an outside villain, who is all too familiar—Pete, henchman of the evil witch Maleficent. It is his discovery of the journal and its worlds that leads to him summoning Maleficent to the journal to wreck yet more havoc for the do-gooders. Once again, their plans are to throw the worlds into darkness and by doing so, ruling as tyrants. It is their intervention that leads to the corruption of the data within Data Riku just as nearly all the data is collected for the journal’s repair, throwing a huge spanner in the works. Thankfully, Riku is un-Bugged and the journal is restored, but even more questions arise.

Upon the journal’s restoration a new world opens up – made of data added by an unknown figure – which is none other than Castle Oblivion. Inside Castle Oblivion, Sora – guided by Mickey – comes across the second Hooded Unknown, presumed to also be Riku; it is actually the data counterpart of Sora’s Nobody, Roxas, who, along with Riku, has been guiding Sora. When Sora refuses to give up his memories, Roxas attacks him but looses the consequent battle, and so Sora learns the truth of the words “We must return to free them from their torment”—Sora holds the memories of all those connected to him; Roxas, Naminé, Xion, Axel, Terra, Aqua and Ventus. It is these people who Sora must free from torment, and now with all the questions answered, Mickey leaves for the real world one last time where he writes the real Sora a letter; it explains that he must return once more to awaken the people connected to him, drawing Kingdom Hearts coded to a close and paving the path for the next adventure.

Set a decade prior to the events in the first Kingdom Hearts, Kingdom Hearts Birth by Sleep follows the three separate, yet intertwined adventures of Keyblade wielders Terra, Aqua, and Ventus, as they together search for the Princesses of Heart and the enigmatic Master Xehanort. As their individual paths take them through a number of fantastic and familiar worlds, the darkness relentlessly pursues, in the form of the shadowy Unversed and the wicked-hearted Disney villains. Till the very end, bonds will be tested to their limits, and when the dust finally clears, a young man named Xehanort will be all that remains.

We first meet our trio of Keyblade wielders in their master’s homeworld, the Land of Departure, a stunningly gorgeous temple surrounded by verdant islands and mist-wrapped mountain peaks. There, the two senior apprentices, Terra and Aqua, ready themselves for their approaching Mastery Qualification Exams under Master Eraqus.

The Exams are not only a means of judging a wielder’s prowess, but also the strength and content of their heart, to see if they are truly able to wield the Keyblade with the power and wisdom of a master. Aqua and Terra gather inside the temple before Master Eraqus, who gives a preliminary speech explaining the details of the Exams. Seated behind him is colleague and fellow master, Xehanort, who traveled from afar to serve as a secondary judge for the Exams.

Following the Exams, Master Xehanort is halted outside the temple by a distraught Terra, whose tests revealed a hidden darkness within his heart. Confused and afraid at the danger lurking inside of him, he implores the master’s wisdom and guidance. Surprisingly, he bids him to nurture the darkness inside him rather than discard it, not even bothering to face Terra as he passes; with power, he lectures Terra, the darkness can be a tool beyond price. But before anyone else in the Land of Departure, including Eraqus himself, comes in contact with Xehanort again, disaster strikes: Master Xehanort inexplicably vanished without warning, and at the same time, a fearsome new threat disrupts the balance of the worlds. The Unversed, strange beings of the darkness that feed on negative emotion, emerge seemingly from nowhere, and begin to wreak havoc amidst the worlds.

Believing Master Xehanort's disappearance, the appearance of the Unversed and the state of the Princesses of Heart are all linked, Master Eraqus sends out his apprentices to find Master Xehanort. The final outcome of the following adventure will not only set the stage for Sora’s quest to stave back the darkness in Kingdom Hearts, but will determine the fate of the entire Kingdom Hearts series. Will Terra overcome the darkness in his heart? What will become of the other apprentices? Remember: “There is no coincidence in fate."

Set between Kingdom Hearts and Kingdom Hearts II is the year long tale ofKingdom Hearts 358/2 Days (read: 358 Days over two). The story follows Roxas, the Nobody born when Sora became a Heartless in order to free Kairi's Heart and prevent the Keyhole to Darkness from exploding. He joins Organization XIII and quickly befriends Axel and Xion, two members who, like himself, want nothing but to become whole. Both Roxas and Xion possess Keyblades, yet they don't remember their pasts. With things never being as they appear, the two struggle to seek answers. Will their pasts reveal who they used to be, and how they received their Keyblades? And what is their relation to Sora, the boy slumbering so he can recover his Memories the Organization scattered?

A week has passed since Roxas joined Organization XIII, a group made out of Nobodies – human beings who lost their Hearts. They strive to become whole again and thus wish to complete Kingdom Hearts, a force that can give them Hearts of their own. That is a task only Roxas can help them with by using his Keyblade, a legendary weapon no other member possesses. That is, until the fourteenth member, Xion, is introduced, sharing both Roxas's age and his ability to wield the Keyblade. Time and effort are put into their education and training, yet the two still manage to find time to themselves in Twilight Town, a sleepy city at the edge of Light and Darkness. There, they meet with Axel, a senior member of the Organization. The three learn the meaning of Friendship together over the salty-sweet flavor of sea-salt ice cream.

The days hardly go by idly, however. Not only do the three have to deal with the never-ending missions assigned by the Organization, they also have their own circumstances to face. Being closest to Saix, the Organization's second in command, nets Axel the ickiest of jobs. Unless he wants to become a Dusk and lose his human self, he has little choice but to oblige. Roxas sees flashes of a boy in red wherever he goes, ones resembling his memories yet with someone else in the middle of them. Fearing he's losing his mind, Roxas begins to question himself while trying to hang onto what he has. Aside from the duties assigned by Saix, he longs for the ice-cream sessions on top of the clock tower in Twilight Town with Axel and Xion. And in the meanwhile, Xion faces off against Riku, a young man deemed an Organization impostor. He wears the coat worn by all members yet isn't one himself, and seems to have a keen interest in Xion and her Keyblade. His words leave her shaken and distraught and it doesn't help at all when Saix begins to treat her as a nuisance.

The doubts slowly grow within each member of the trio. Unable to balance their own dilemmas and each other's needs, their friendship is put to the ultimate test. Can Roxas and Xion truly trust Axel, who keeps so much from them? Without remembering his past and where he came from, can Roxas know where he's headed? If he's where he belongs? Xion turns ironically to Riku, who seems to have all the answers, but what will she choose? Staying with the friends she cares for so deeply, or setting things as they should be, and put an end to Sora's sleep? Their friendship might not last their misguided decisions as the days pass by.

Kingdom Hearts: 358/2 Days (read: 358 Days over two) begins near the end of Kingdom Hearts and Kingdom Hearts II and includes within it the events of Chain of Memories. It follows Roxas, the Nobody of the Keyblade Wielder Sora, and tells the tale of his time as a member of Organization XIII. There, he meets Xion and Axel, his two best friends who together struggle with their own pasts and the Organization's plots to use them for their own ends. Remaining true to themselves is something all three strive to achieve, yet doing so might cost them more than their own lives, but also each other as the Organization strives to obtains the power of Sora's Keyblade at all costs.

Human beings are capable of losing their Hearts. What's left behind are the Body and Soul that together make up "leftover" beings called Nobodies. Organization XIII is made up of such Nobodies, specifically ones that managed to maintain their human forms. Their goal is to become whole again and for that end, they wish to complete Kingdom Hearts, a force that can grant them Hearts of their own.Roxas, the Nobody of Sora, the Keyblade Wielder, is the XIII member of the Organization. Using his Keyblade, he is to defeat the lost Hearts that became Heartless and thus create Kingdom Hearts. He quickly befriends Axel, the Organization's Number VIII and learns the meaning of friendship from him. When Axel is sent to Castle Oblivion under the Organization's orders, Roxas applies what he learned with Xion, the new XIV member of the Organization. Much like him, Xion is a wielder of the Keyblade, yet it seems the two's abilities are related.

Shortly after the plan in Castle Oblivion fails, Roxas falls into a coma, and once he wakes, Xion loses the ability to Wield her Keyblade. After spending time with Roxas she regains her Keyblade, and at that time Saix attempts to use his past relations with Axel in order to get him to spy on Xion and Roxas. The importance of that task is shown when Xion meets Riku, Sora's childhood friend who is trying to help Sora wake up from the sleep he fell into after the incident in Castle Oblivion. He seems to know about Xion's true nature and her Keyblade more than Xion herself does, and that fact along with a warning to leave the Organization leave Xion shaken and distraught. She eventually falls into a coma during which she connects to Sora's Heart and absorbs more and more of his Memories. Realizing they are not her own, however, she seeks answers and eventually finds them from Riku. She is a Replica created by the Organization who initially had no identity of her own, and not even a face. Once Sora went to sleep his Memories began leaking out into Roxas and from him into Xion, and eventually shaped her. In order for Sora to wake up both Xion and Roxas must be returned to him, but Riku gives Xion the time to reach her own decisions, refusing to force her into anything.

The two escape the Organization for a while as Xion figures things out and eventually she engages Roxas and Axel. She and Axel fight and he manages to bring her back, yet due to the violent nature of his actions, Roxas can't forgive Axel.

Now closer again to Roxas, Xion begins to take from him more than just Sora's Memories and takes his powers as well. Using the Keyblade becomes more and more difficult for Roxas to the point the Organization pits the two against each other in the hopes only one would remain, bearing all the power and is thus useful. Realizing there is no other way, Xion loses to Roxas and is absorbed by him, only to fade out of everyone's Memories. As Sora's Memories were what shaped her, giving them back means there will no longer be a 'Xion' to remember. Clinging onto those fading Memories, Roxas wishes to take on the Organization in the hopes it might bring Xion and his friendship with Axel back, yet he is intercepted by Riku who manages to defeat Roxas and brings him back to Sora. From within, Xion offers reassurance as the Memories she shared with Roxas will forever more live within Sora, but they bear nothing but empty promises as Roxas himself is slowly lost inside the one he came from.