She is the daughter of Ragyō and Sōichirō Kiryūin, the president of Honnōji Academy's Student Council and the ruler over its surrounding land. She has absolute authority over the academy and is regarded with reverence by many of its residents.She is the main antagonist for the first half of the series with an anti-villain motive, and eventually becomes a deuteragonist in episode 17 when her mother Ragyō Kiryūin takes the role of the antagonist for the remainder of the series.