Yuuki Konno is a new player who appears in ALfeim Online in volume 7. She leads the Sleeping Knights guild and quickly becomes known as one of the strongest in the game winning 67 straight matches, earning her the title of “Absolute Sword.”
Her guild, the Sleeping Knights, is a group of terminally ill patients who play using the FullDive Technology MediCuboid. Yuuki’s disease is AIDS which she obtained through a bad blood transfer she received as a child. Her parents and older twin sister were also infected. She was bullied in school after it was known she was a carrier, causing her to transfer schools. However, her condition drastically deteriorated, worsened by the rejection from the parents and teachers of her old school. She was then later taken to a hospital where she lived the next 3 years in the new medical FullDive Technology called MediCuboid. It is due to this that her experience in the VR world exceeds even that of the survivors of Sword Art Online, and for this reason, she can even defeat Kirito in a fair match when he isn’t dual wielding. Kirito claims, however, that even if he was dual wielding, he would still be unable to defeat her. Kirito also admits that if she was a victim in the Sword Art Online Incident, she would have been the one to receive the Dual Blades sword skill which is awarded to the player with the fastest reaction time.
She is also the creator of the 11-hit Original Sword Skill “Mother’s Rosario,” which is later given to Asuna as her “only form of way” of protecting and repaying her.
Yuuki is the second leader of the Sleeping Knights guild who inherits it after her older twin sister Aiko, the founder and former leader, died one year prior to the events of the Mother’s Rosario arc. Her parents died the year before. She quickly becomes friends with Asuna due to the the fact that she looks similar to Aiko.
She becomes the best of friends with Asuna, even in real life. She jokingly proposes to her so that if she joins Asuna’s family, her name would be “Yuuki Yuuki” as Asuna’s last name is Yuuki. Asuna goes to great lengths to ensure that Yuuki can enjoy the “real” world again after the trauma she has experienced previously. However, Yuuki’s physical body can never leave the Medicuboid, which leads to Kirito developing a VR camera for her so that she can attend the SAO Survivor School. Throughout the series, Yuuki’s condition gradually worsens to the point where she can barely even stay conscious in the VR world. She spends the last moments of her life in ALfeim Online embraced in the arms of Asuna surrounded by her friends and thousands of fellow ALO players, passing away in happiness.