The Data Riku is a character appearing in Kingdom Hearts coded and its remake, Kingdom Hearts Re: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.
The 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 Block 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 Data World.
The 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 Twilight 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 Block 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 Blocks fused with his body. Mickey arrives and tells Sora that unless all the bugs in his 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.