Prior to becoming known as Yuuki of ALO, Yuuki Konno was a child suffering from "Acquired Immunity Difficiency Syndrome" (AIDS) since birth; her parents, as well as her sister Aiko, were infected too. Despite this, she had always believed that one day she would be healed and continued to strive towards her goals. However, during the course of 4th grade, a group of students found out that Yuuki was a carrier of HIV and began spreading rumors about Yuuki. Because of this, Yuuki was forced to transfer to another school. After transferring to a new school, Yuuki's condition gradually became worse and the reason suspected by her doctor was from the rejection caused by the parents and teachers of her old school. Her parents died two years ago, and her sister the year before the events of Mother's Rosario.
- Yuuki also acknowledged Kirito as being as strong a player as Asuna, yet she didn't ask for his help because he had discovered her secret as a user of the MediCuboid.
- Kirito claimed that if Yuuki had played SAO, she would have been the one to receive the Dual Blades skill, as her reaction speed was greater than his.
- As a MediCuboid user, she was one of the few people who had more playtime than the "survivors from the SAO incident", having logged on for over three years online.
- She jokingly proposed marriage to Asuna and told her that Asuna would have to join Yuuki's family, because if Yuuki joined Asuna's family she would be named Yuuki Yuuki (Yuuki is also Asuna´s last name).
- Yuuki is the second person known to have used their real name as their in game name (the first being Asuna).