Yūko Asou is a protagonist in the visual novel series Valis X. A seemingly ordinary girl who goes to high school. She's an honor student, but has a lax and carefree attitude. She's actually from Vecanti and is destined to be a Valis warrior. Altruistic and brave. She's also a Parallel universe traveler. Yuuko is awaken as a soldier of Vais. She fights to save the world called vanity, and Vecanti, a monster from the dark world stood in the way.
- She's defined as a homosexual character in the visual novel.
- In one of the chapters, she touched a certain girl.