Project Alicization

Project Alicization is a top-secret government project run by RATH using the fourth generation FullDive technology, Soul Translator. Their goal is to create intelligent Artificial Intelligence, for what they're using NPCs. What's special about this AIs is that the "learn" as a human does, their problem is that this AIs are meant to fight in wars instead of humans, but they can't kill anyone because of the laws they've been instructed into. The virtual world that houses these AIs is called, by the creators, Underworld: the name may or may not be connected to the original name of Alice's Adventures in Wonderland; Alice's Adventures Under Ground. The facilities that have connections to it are in Roppongi and the Ocean Turtle (A marine base that kind of looks like the Mock Turtle from the story).

For experimenting they insert Kirito in the Underworld and, to their surpize, the people who interacted with Kirito were closer to break the rules than the others, they continue until one day a girl, that by coincidence is called Alice, was induced into breaking the parameters of the game.