Kirito is the main protagonist of the Sword Art Online series. His name in game was taken from his real life name, Kirigaya Kazuto (桐ヶ谷 和人), the first and last kanji of his name. When the very first VRMMORPG called Sword Art Online was released, Kirito was chosen as one of the 1.000 beta testers. The technology for the game is NerveGear.
Kirito is a person who is bad with words, and can be quite direct. This is because of him not having so much friends and closing others off because of his family status and very passionate for computers. As such, sometimes he can be a rude person to others. But occasionally, he actually seems to enjoy teasing and angering peope, too. Likewise, from time to time, Kirito can be very overconfident thinking he can do things others can’t.
He’s almost always a collected and calm person, rarely showing any signs of distress. Through out the series he has shown different moods, at times being cheerful, while being gloomy. When in a battle, he turns into incredilty aggressive and enjoying the fight. Sometimes, his fierceness is up to the point where he seems to lose control of himself and is unable to recall what he had done.
However, Kirito is really a kind person who is merely misunderstood. Despite the general population judgment towards beta testers in SAO, he declined to abandon another player in trouble. This is merely increased after the demise of Moonlit Black Cats. He also comforts others who ace down or scared.
Kirito could also a very emotional person and allows his feelings control him every now and then. He is a person with extremely strong resolve who will everything and anything in his power to accomplish something that is essential to him without the hesitation.