Yuuki Konno, often referred to as simply Yuuki, is a pivotal character from the 'Sword Art Online' series. She is introduced in the 'Mother's Rosario' arc as a vibrant and highly skilled player in the game 'ALfheim Online' (ALO). Known for her exceptional swordsmanship and agility, Yuuki is the leader of the guild 'Sleeping Knights.' Despite her cheerful demeanor, Yuuki faces a tragic reality in the real world, suffering from a terminal illness. Her story profoundly impacts the main character, Kirito, and his friends, leaving a lasting legacy within the series.