- Official name:アスナ / 結城明日奈
- English name:Asuna Yuuki
- Chinese name:亚丝娜 / 结城明日奈
- Other names:ゆうき あすな / Yuki Asuna
- Gender:Female
- Birthdate:Sept 30, 2007
『Asuna Yuuki』
Birthdate: September 30, 2007
Age: 15 (Beginning of Aincrad arc); 17 (End of Aincrad arc, Fairy Dance arc); 18 (Phantom Bullet arc, Alicization Arc)
Height: 168 cm
Weight: 55 kg
Three Sizes (BWH): 82-60-83
Weapons of choice: Wind Fleuret (1st Floor), Lambent Light (Forged by Lisbeth)
Asuna is a friend of Kirito and is a sub-leader of the guild Knights of the Blood (KoB), a medium-sized guild of about thirty players, also called the strongest guild in Aincrad. Being one of the few girls that are in SAO, and even more so that she's extremely pretty, she receives many invitations and proposals. She is a skilled player earning the title "Flash" for her extraordinary sword skill that is lightning fast. Her game alias is the same as her real world name.
She is married to Kirito in SAO. They decide to live a peaceful life and to buy a house on the lower part of Aincrad and take a break from the guild Knights of the Blood Oath. But later they need to return to the front lines, abandoning their peaceful life.After the SAO incident, all the players that survived should have awoken, but Asuna is still trapped within her NerveGear. She is actually abducted by her betrothed, Sugou Naboyuki, who transfers her to Alfheim Online (ALO).In ALO, She is known as Queen Titania, yet she is only a character who is trapped within a cage that is programmed to be an unbreakable object. She was rescued by Kirito who became a Game Master by accessing Heathcliff's account, and defeated Sugou. Kirito logged Asuna off from ALO and rejoins her in the hospital after he ended his fight with Sugou in the real world.