Data-Riku is a character that appears in Kingdom Hearts coded. He is the digital counterpart of Riku, formed from the data contained in the digitized Jiminy's Journal, as well as a vessel for the memories contained within the journal.
Data-Riku had bound the memories contained within Jiminy's Journal together when they were strewn apart, but this restoration could not be completed because of the Bug Blox infestation. Of all the memories inside the Journal, he was selected to be a vessel to hold the memories together and protect them from corruption. He even involved King Mickey, Donald, Goofy, and the Data-Sora in this process to solve the mystery of the strange words that continued to appear in Jiminy's Journal by transferring Disney Castle to the Datascape.
Data-Riku continues to aid the protagonists throughout the story, but he is eventually captured by Maleficent and Pete, the latter using bugs to force Data-Riku to fight Data-Sora. Data-Sora is then tasked with debugging Data-Riku's data.
 Kingdom Hearts coded
Data-Sora encounters a black-coated figure on the digital Destiny Islands, who gives him cryptic clues and leads him to a Keyhole. The figure reappears in the data versions of Traverse Town and Wonderland, giving more cryptic messages and occasionally lending Data-Sora assistance as he works to destroy the bugs and corruption in the worlds' data. After debugging the data for Wonderland, Data-Sora follows the figure to Disney Castle, where he meets Mickey, Donald, and Goofy.
At this time, the black-coated man reveals himself to be Data-Riku. He explains that he has been given possession of the memories contained in Jiminy's Journal, and that he brought Mickey, Donald, and Goofy into the data world in order to solve the mysterious message, "We must return to free them from their torment", that appeared in the journal.
As Data-Sora continues visiting the worlds in the journal, Data-Riku stays in Disney Castle, guiding Sora through the monitor. When Data-Sora reaches the digital Olympus Coliseum, Riku tells him that the reason he did not reveal himself to Sora earlier is because he wanted Sora to become stronger. He discusses with Sora whether they are data or artificial, and Riku says that it does not matter as long as they can make an impact to the world and help their friends.
Data-Riku reveals that the reason the monitor kept showing things Jiminy never wrote about is because it shows the journal's sleeping memories, but that even he does not know the reasons for the mysterious messages appearing in the journal, the Bug Blox corruption that appears in the Data Worlds, or what is happening to the Data World.
When Maleficent destroys Data-Sora's Keyblade in Agrabah, Data-Riku and Mickey come to help. However, Maleficent and Pete capture Riku and take him to Hollow Bastion, where they infect him with bugs. Later, when Data-Sora defeats Pete in Hollow Bastion, he summons the bug-controlled Data-Riku to fight Sora. After Sora defeats Riku, Riku collapses, with Bug Blox fused with his body. Mickey arrives and tells Sora that unless all the bugs in his body are destroyed, Data-Riku will never wake up.
Data-Sora uses his Keyblade to enter Data-Riku's data, meeting with Riku's consciousness. Riku leads Sora through his memories to destroy the bugs and to recover his own power. After Sora destroys the source of the bugs, a corrupted version of Riku himself, Maleficent tries to interfere with Data-Riku's recovery. Data-Sora defeats Maleficent, and Riku awakens.
As the data in the journal finishes debugging and collecting, it begins resetting the Data World to its original form. However, Sora's Heartless interferes, and the world begins deleting itself. Riku tells Sora about the nature of his Heartless and rescues Pete and Maleficent. After Data-Sora defeats his Heartless, the Data World is reset, but Data-Riku partitions off part of his data, containing his memories. He then notifies Mickey, Donald, and Goofy of the appearance of Castle Oblivion in the data world.
Data-Riku makes one more appearance, in the first White Room in Castle Oblivion. He shows Data-Sora a memory of the real Riku and a heartless Kairi on the Clock Tower and encourages Sora to push forward, even if he finds himself in torment.
Data-Riku takes on the form of Riku's 15 year-old body as it appeared in Kingdom Hearts and Kingdom Hearts: Chain of Memories. He is mainly seen wearing the Black Coat of Organization XIII, but while his data is full of bugs, he wears the same bodysuit the real-world Riku wears in Dark Mode.
The bugged version of Data-Riku is completely black version of him in his Dark Mode, resembling a silhouette, and wields a dark versions of Soul Eater. Data-Riku's body and Soul Eater are covered in and surrounded by bugged browser windows, which vary in color depending on what form of bugs currently make up this Data-Riku.
Data-Riku also acts in a fairly similar manner to his real-world counterpart. He is shown to care greatly for Data-Sora, even wanting him to become stronger as well. Data-Riku is calm and cool, much like the real Riku was in Kingdom Hearts. When under the influence of the Bug Blox, Data-Riku's personality greatly changes to give him a more aggressive persona.
The only major difference between Data-Riku and the real Riku's personalities would be Data-Riku's sense of responsibility. This is demonstrated by Data-Riku's wish to solve the mystery of the strange messages appearing in Jiminy's Journal and also to keep the memories contained within him safe from corruption.
One of the many similarities between Data-Riku and the real Riku is the arsenal of abilities they can use in battle. Data-Riku can not only use Dark Shield and counter if the barrier he places before himself is hit (something Riku demonstrated during the battle with Roxas in Kingdom Hearts 358/2 Days), but he can also use the deadly Dark Aura ability (something Riku has demonstrated in all appearances). Data-Riku is also capable of vanishing temporarily and striking the ground soon after, causing several Bug Blox to spawn. Lastly, Data-Riku is able to wield a data version of the Soul Eater, a weapon used in the real world by Riku.
As the vessel of the memories of Jiminy's Journal, he also has the ability to manipulate data. He has the ability to access the journal's memories, with it becoming easier as the bugs are destroyed. He also is the one who brings Mickey, Donald, and Goofy into the Data World, and he opens the passage for them to return to the real world. He can partition his data to protect his consciousness and memories from corruption or deletion, and he creates passages for Data-Sora to enter his memories and to leave his data. Unless there is interference, he can also lock down the data in the journal in case of emergencies.
 Fighting style
Data-Riku is fought in two multi-phase battles. The first battle takes place in the Data Hollow Bastion. The second battle takes place within Data-Riku himself. While he only uses simple slashes and Dark Shields in the first phase of both battles, he gets more aggressive in later phases, using the same agility and abilities as the real Riku.