"Kirito" is the character name of a Japanese teenager named Kazuto Kirigaya (キリト / 桐ヶ谷和人（きりがや かずと）) who is create by Reiki Kawahara. In the virtual reality MMORPG Sword Art Online, players use a VR headset called the NerveGear that transplants the player's mind entirely into the game. Kirito takes part in the beta testing period of the game and thus had more experience with it before its official release date.
Light Novel, Anime, and Manga Adaptations
On the game's launch day, Kirito meets a newbie named Klein, whom he befriends and helps out. However, the two of them later discover that they cannot log out. Akihiko Kayaba, the creator of SAO, addresses the 10,000 online players of the game and informs them that they will not be able to log out until the game is cleared, and that dying in the game will kill the player in real life.
Kirito spends the next 2 years helping to clear the game. He cooperates with player guilds for important boss raids, but otherwise develops an image as a powerful solo player, becoming known as the Black Swordsman, for his preference for black clothing.
Early on, he develops a bad reputation as a "beater" (portmanteau of "beta tester" and "cheater") because of the fact that he was a beta tester, yet was unwilling to reveal himself as such and thus deprived other players of valuable information on the game. This stigma, along with the anguish of having players around him die, leads him to fight as a lone wolf for most of his time in the game.
Kirito later mysteriously and inexplicably receives the Dual Wielding skill, allowing him to fight with two swords at once. He at first tries to conceal this ability for fear of being targeted by other players, but tends to use it in extreme situations.
Kirito becomes close to another player in the game, Asuna, and they later become romantically involved and marry in-game.