Kirigaya Kazuto was born on October 7, 2008. When he was young, his parents died in a car crash, leaving his aunt to care for him. While growing up in a traditional Japanese family, he and his sister Suguha was forced by their grandfather to practice kendo. However, he took after his aunt, quitting the sparring practice and instead, playing with technology items by the time he was at the age of six. He, by himself, was able to create his own computer that worked.
At ten, he realized his true blood: he was only the nephew of his mother, Kirigaya Midori, and Suguha was his sister. Distraught, he turned his full attention to videogames. He started with the advanced technology of the computer, but soon a new type of technology that immerses all senses to the game: NerveGear. Kazuto was chosen as one of the 1000 beta testers one month before the official release of Sword Art Online, a virtual roleplaying game. His obsession took over him; he would, as soon as he got home, enter into the addicting roleplaying game.
One month passed. The day Sword Art Online was released the public, November 6, 2022. Kirito happily logged on, suspecting nothing wrong. He acted happy to return to his second home, and another player, a new player, Klein, chased him down. Klein requested that Kirito teach him the basics of the game, to which the latter happily obliged. Four hours into the game, the absolute change turned all the 10,000 players that logged into the virtual environment life around. Kayaba Akihiko, creator of Sword Art Online, appeared as the absolute ruler of Aincrad and he told them that this game is a death trap. Monsters are able to kill a player; suicide is able to wipe a player from the face of the real earth. All players will turn into their real bodies and the only way to escape is to clear the game.
Kirito, being one of the beta testers, promised himself that he will help the other players to clear the game. One misstep could destroy each player. Kirito vowed that no matter what cost, he will do the best he can to return everybody to the real world.