Kirito

Around 4:00 AM on December 2, 2022, almost a month since the game's service began, Kirito encountered a hooded player fighting a Ruin Kobold Trooper on the nineteenth level of the 1st Floor labyrinth. While impressed by the player's skill with a katana, the former beta tester hesitated before revealing himself to the fencer after the fight to comment on the ineffectiveness of using Sword Skills on a nearly dead enemy.

During his conversation with the hooded player, Kirito realized that he was talking to a girl based on her voice, and was surprised by her disregard for her self-preservation, the time she had spent in the labyrinth, and the condition of her equipment. When the player fainted shortly before being able to leave, the swordsman took her to the forest outside the labyrinth and waited for her to recover. Seven hours later, the girl woke up, wishing to return to the Labyrinth again, so Kirito suggested going to the First Floor Boss Strategy Conference in Tolbana if she truly wanted to beat the game, rather than just dying pointlessly.

Kazuto described his early SAO avatar's appearance as having the appearance of a ridiculously handsome protagonist from some fantasy anime, while looking noticeably older than he actually was. His height in the game was set to the same as his real-world height, to prevent the extra height from creating glitches in his movements.

In the full version of the game, during Kayaba Akihiko's introduction, all of the game's avatars were changed to reflect their real-life appearances. After this change, Kirito's SAO avatar had slightly longer, but sleek black hair and black eyes. His delicate face showed no trace of masculinity, allowing people to easily mistake him for a girl.

After the initial stage, Kirito is known in SAO as the Black Swordsman. This is due to his tendency to wear black clothing. His clothing in Sword Art Online consisted of black pants with a black belt that had a large silver buckle, a black V-neck shirt that was worn under a black trench coat with gray lining under the sleeves, and black boots with silver plates to protect his shins. He had a silver vest worn on the left side of his coat, and a pair of black fingerless gloves. He wore a belt, which went over his right shoulder diagonally from the left side of his waist, and at first held only his sword, Elucidator, but later came to hold his Dark Repulser as well.

Kirito used two swords after his sword skill, "Dual Blades", was revealed, the Elucidator and the Dark Repulser.

Kazuto Kirigaya, born Narusaka Kazuto, and known as "Kirito" in Sword Art Online (SAO).

Character: Kazuto isn't good with words and, as stated by Klein, can be quite blunt. This stems from the fact that he's very reserved and doesn't have many friends. Because of this, he can be seen as a rude person by others. Kazuto seems to enjoy irritating and provoking other people. Furthermore, he can be overly confident when it comes to his abilities, believing he's capable of doing things others can't.
He is almost always a calm and composed character; however, it is not uncommon for him to show signs of distress. During the Sword Art Online tutorial, when Kayaba Akihiko appeared and announced that SAO had become a death game, Kazuto showed only a slight reaction and was able to quickly accept the new conditions of the game, while many others panicked. In battle, he becomes incredibly fierce and aggressive. Sometimes, his ferocity reaches the point where he loses control of himself and is then unable to remember what he did.
However, Kazuto is actually a kind person. He is, however, misunderstood. Despite the general opinion about beaters in SAO, he, shortly after the game began, avoided abandoning other players in trouble as much as possible. He also helped other players who were scared or apprehensive, such as "Silica," after she lost Pina. Kazuto also feels remorse for not having maintained a good relationship with his sister, Suguha, and for abandoning Klein at the beginning of the game.

Details: In Aincrad, Kirito always kept his swords on his back, and maintained a second sword in his inventory for use only in extreme situations, but only began to show it normally after the events on the 74th floor.

Kazuto is also a very emotional person, and in some cases, this allows his emotions to control him. The deaths of the Moonlit Black Cats guild members haunted Kirito. Sachi's death in particular had a huge effect on his personality and motivation, causing him to become very distant from others for a time. He also prefers to hide his abilities, so as not to attract unnecessary attention.