The humanity was destroyed by the quantum artificial intelligence. Omniscient was a global service program powered by quantum processors - the most perfect program ever created. Everyone died in less than a day. No one knows what happened and what were the reasons - cause there's no one anymore.
The fact that Kenzo lives is a set of circumstances. He was grown artificially after the apocalypse by Acine, an assistant AI, deep under the ground in an isolated place called CELL. It meant to be a secure residential complex system for the powers that were. The one that Kenzo lives in wasn't finished. It is barely operative. He doesn't even know why he's there, cause he's not authorised to possess this information. He had some chances to socialise and get some education with social simulations and Acine, but it is not enough to keep the young man's mental stability. He seems to be okay, but he's not okay. And as much as he'd like to meet just anyone alive, is he really ready for it?
FYI: Some of the game's dialogs contain technical terminology and references that may not be self-explanatory to players without informational technology education.