Kirito キリト
Real name: Kazuto Kirigaya
Kirito is a "solo" player and has been branded a beater (beta tester and cheater) by the players in Sword Art Online. His power levels to improves as he quickly emerging as a front line clearer of floors known as the Black Swordsman. In SAO, he is the sole possessor of a unique skill, «Dual Blades». During his time in SAO, he falls in love with a female player, Asuna, and even marries her in-game. Later, in Alfleim, he can still manually use two swords and has developed two new Outside System Skills
Kirito is a "solo" player and has been branded a beater (beta tester and cheater) by the players in Sword Art Online. His power levels to improves as he quickly emerging as a front line clearer of floors known as the Black Swordsman. In SAO, he is the sole possessor of a unique skill, «Dual Blades». During his time in SAO, he falls in love with a female player, Asuna, and even marries her in-game. Later, in Alfleim, he can still manually use two swords and has developed two new Outside System Skills
Klein クライン
Real name: Ryōtarō Tsuboi
A friendly player that meets Kirito at the start of the game, who quickly befriends and learns from Kirito. They go their separate ways shortly after when Kirito leaves for another town to power up, while Klein remains behind to help out his less experienced friends. Klein uses a katana to fight and later becomes a leader of his own guild. He reunites with Kirito after two years in the 74th floor dungeon. He regularly meets with Kirito and his friends and occasionally joins them in quests in ALO.
A friendly player that meets Kirito at the start of the game, who quickly befriends and learns from Kirito. They go their separate ways shortly after when Kirito leaves for another town to power up, while Klein remains behind to help out his less experienced friends. Klein uses a katana to fight and later becomes a leader of his own guild. He reunites with Kirito after two years in the 74th floor dungeon. He regularly meets with Kirito and his friends and occasionally joins them in quests in ALO.
Egil
Real name: Andrew Gilbert Mills
Bald axe wielder who owns a shop in SAO. Agil is tall with a muscular build. Despite his intimidating appearance, he is kind-hearted and spent most of his earnings to help players in the middle floors. Kirito is a regular in his shop and they are friends. Agil runs a shop named «Dicey Cafe» in the real world, which was run by his wife during his two-year coma. The cafe later becomes Kazuto and company's meeting place in the real world.
Bald axe wielder who owns a shop in SAO. Agil is tall with a muscular build. Despite his intimidating appearance, he is kind-hearted and spent most of his earnings to help players in the middle floors. Kirito is a regular in his shop and they are friends. Agil runs a shop named «Dicey Cafe» in the real world, which was run by his wife during his two-year coma. The cafe later becomes Kazuto and company's meeting place in the real world.
Asuna アスナ
Real name: Asuna Yūki
Asuna friend of Kirito and is a co-leader of the Knights of the Blood Oath, a medium-sized guild, the strongest guild in Aincrad. Asuna strong-willed, accomplished player known in-game as the "Flash" for her extraordinary sword skill. Later, she falls in love with Kirito and they marry in-game. Despite the completion of SAO, Asuna does not wake up and is instead imprisoned in another VRMMORPG called Alfheim Online. She is forced to play the role of Titania the Queen of Fairies, with Nobuyuki Sugō, the man responsible for imprisoning her.
Asuna friend of Kirito and is a co-leader of the Knights of the Blood Oath, a medium-sized guild, the strongest guild in Aincrad. Asuna strong-willed, accomplished player known in-game as the "Flash" for her extraordinary sword skill. Later, she falls in love with Kirito and they marry in-game. Despite the completion of SAO, Asuna does not wake up and is instead imprisoned in another VRMMORPG called Alfheim Online. She is forced to play the role of Titania the Queen of Fairies, with Nobuyuki Sugō, the man responsible for imprisoning her.
Silica
Real name: Keiko Ayano
One of the rare beast tamers in the game. She, very early in the game was able to tame a dragon which gave her immense fame, but she was just a mid-level player. Due to her fame and being a girl, many tried to get on her good side, causing her to get a bit of an inflated head. After getting lost in a forest, she lost her beast and only friend in the game. Kirito rescued her, and helped her as she resembled his sister. She gained feelings for him, but once she realized his skills, she realized that they could never be together in the game. Later on it is revealed that Pina (her beast) was revived. She joins Kirito and his friends in ALO right after they meet in the real world; they often go together in quests.
One of the rare beast tamers in the game. She, very early in the game was able to tame a dragon which gave her immense fame, but she was just a mid-level player. Due to her fame and being a girl, many tried to get on her good side, causing her to get a bit of an inflated head. After getting lost in a forest, she lost her beast and only friend in the game. Kirito rescued her, and helped her as she resembled his sister. She gained feelings for him, but once she realized his skills, she realized that they could never be together in the game. Later on it is revealed that Pina (her beast) was revived. She joins Kirito and his friends in ALO right after they meet in the real world; they often go together in quests.
Sachi サチ
She was a member of "Black Cats of the Full Moon" which was the first guild Kirito joined. Kirito was especially attached to her. However she died along with the majority of her guild members which led to Kirito wallowing in despair and self-loathing until he read the time delayed message she left for Kirito. Even after the message gave him the strength to live, he never joined another guild until the events of Volume 1.
Lizbeth
Real name: Rika Shinozaki
A blacksmith with her own shop. Lizbeth or "Liz" is a close friend of Asuna who recommended her to Kirito. Kirito commissioned Liz to forge a custom-made sword for him and accompanies her in a quest for the special ore required for the job. During the quest, she also develops feelings for Kirito. She is devastated when she finds out that Kirito is Asuna's crush. However, she finds some solace after Kirito thanks her for giving him a renewed determination to fight on and clear the game. Liz later becomes a regular player in ALO, and frequently joins Kirito and his friends in quests and takes up the task of upgrading their equipment.
A blacksmith with her own shop. Lizbeth or "Liz" is a close friend of Asuna who recommended her to Kirito. Kirito commissioned Liz to forge a custom-made sword for him and accompanies her in a quest for the special ore required for the job. During the quest, she also develops feelings for Kirito. She is devastated when she finds out that Kirito is Asuna's crush. However, she finds some solace after Kirito thanks her for giving him a renewed determination to fight on and clear the game. Liz later becomes a regular player in ALO, and frequently joins Kirito and his friends in quests and takes up the task of upgrading their equipment.
Yui ユイ
She is actually an artificial intelligence program. Her full designation is «Mental Health - Counselling Program», MHCP version 1, codename, «Yui». She was designed to monitor the emotions of players and appear at their sides to hear and help them out. However, since the moment everyone was imprisoned in Sword Art Online, she was forbidden to come in contact with the players and complete her prime directive. Unable to do anything but suffer as she monitored the emotions of the trapped players, she came upon Kirito and Asuna whose emotions stood out as a beacon of joy and peace in a sea of fear and despair. She sought them out, appearing to them as an amnesiac child whom they adopted. In the end she was nearly deleted by Cardinal, the management system of SAO. But Kirito saved her by converting and storing her data into his own Nerve Gear. Yui later shows up in ALO as a Private Navigation Pixie and helps Kirito along with Leafa to find Asuna. She refers to Kirito as "Papa" and Asuna as "Mama" and gets very annoyed if any girl other than Leafa or Asuna gets close to Kirito. Kirito uses his skills and resources in the real world to construct a device for Yui to view the real world even while she is in virtual reality and gives her the ability to communicate with them.
Heathcliff
Real name: Akihiko Kayaba
Kayaba is the Director and creator of the Nerve Gear and Sword Art Online, as well as the main antagonist of the Sword Art Online arc. He traps all the players within Sword Art Online by using the Nerve Gear to cease sending signals to the users' body. Any in-game death or attempt at removal of the Nerve Gear would result in the real life death of the user. Later, it is discovered that he has been masquerading as Heathcliff, the leader of the Knights of Blood. Although he has the admin powers to make his avatar immortal, he is shown to be a powerful player even without his in-game immortality due to his intimate understanding of the SAO game mechanics which he himself had designed. He is defeated by Kirito at the end of Volume 1 and, at the end of Volume 4, leaves behind a program that grants Kirito the World Seed. His death was his own doing since he had also rigged his own Nerve Gear device to fry his brain when he was defeated.
Kayaba is the Director and creator of the Nerve Gear and Sword Art Online, as well as the main antagonist of the Sword Art Online arc. He traps all the players within Sword Art Online by using the Nerve Gear to cease sending signals to the users' body. Any in-game death or attempt at removal of the Nerve Gear would result in the real life death of the user. Later, it is discovered that he has been masquerading as Heathcliff, the leader of the Knights of Blood. Although he has the admin powers to make his avatar immortal, he is shown to be a powerful player even without his in-game immortality due to his intimate understanding of the SAO game mechanics which he himself had designed. He is defeated by Kirito at the end of Volume 1 and, at the end of Volume 4, leaves behind a program that grants Kirito the World Seed. His death was his own doing since he had also rigged his own Nerve Gear device to fry his brain when he was defeated.
Lyfa
Real name: Suguha Kirigaya
Kirito's younger cousin in the real world. Lyfa is a diligent worker and has been practicing Kendo for 8 years. Kirito calls her "Sugu". After Kazuto gets trapped in Sword Art Online, she begins playing ALfheim Online in an attempt to understand him better. She develops feelings for Kazuto after she learns that he is not really her brother, but understands that his feelings for Asuna are too strong. Coincidentally, she meets Kazuto's avatar, Kirito, in ALfheim and aids him in his search for Asuna, unaware of Kirito's true identity. After understanding the depth of Kazuto's love for Asuna, she resolves to give up on him and instead becomes attached to Kirito in ALO, but later is heartbroken when she finds out that Kazuto and Kirito are one and the same. Nevertheless, she pulls herself together and aids Kirito in rescuing Asuna.
Kirito's younger cousin in the real world. Lyfa is a diligent worker and has been practicing Kendo for 8 years. Kirito calls her "Sugu". After Kazuto gets trapped in Sword Art Online, she begins playing ALfheim Online in an attempt to understand him better. She develops feelings for Kazuto after she learns that he is not really her brother, but understands that his feelings for Asuna are too strong. Coincidentally, she meets Kazuto's avatar, Kirito, in ALfheim and aids him in his search for Asuna, unaware of Kirito's true identity. After understanding the depth of Kazuto's love for Asuna, she resolves to give up on him and instead becomes attached to Kirito in ALO, but later is heartbroken when she finds out that Kazuto and Kirito are one and the same. Nevertheless, she pulls herself together and aids Kirito in rescuing Asuna.
Oberon the Fairy King 妖精王オベイロン
Real name: Nobuyuki Sugō
Main antagonist of the Alfheim Online arc. He is the one responsible for keeping 300 Nerve Gear victims, including Asuna, prisoner even after SAO had ended. He also attempts to take over RCT Progress Inc. by marrying Asuna while she is unconscious are his goals. In ALO, he takes on the identity of Oberon the Fairy King and makes Asuna his queen, Titania. When he and Kirito finally meet, he flaunts his GM status as well as the results of his research by causing Kirito immense amounts of pain after increasing Kirito's pain limit and impaling him
Main antagonist of the Alfheim Online arc. He is the one responsible for keeping 300 Nerve Gear victims, including Asuna, prisoner even after SAO had ended. He also attempts to take over RCT Progress Inc. by marrying Asuna while she is unconscious are his goals. In ALO, he takes on the identity of Oberon the Fairy King and makes Asuna his queen, Titania. When he and Kirito finally meet, he flaunts his GM status as well as the results of his research by causing Kirito immense amounts of pain after increasing Kirito's pain limit and impaling him