Kayleigh Glanzelius attends Seio Girls' Academy, one year junior to Kaoruko Nanahara. She proclaims herself the "Star Princess" (Hoshi no Oujo). Her mixed heritage, with an Asian father and Northern European mother, grants her distinctive olive skin and a European-style name that sets her apart at school.

Entering Seio without prior formal schooling led to initial friction due to socialization gaps. Embracing her non-conforming status, she deliberately cultivated an air of mystery during her first year. By her second year, she consciously shifted to a more feminine demeanor, abandoning earlier masculine speech patterns.

Standing 171 cm tall, Kayleigh possesses ochre/brown hair styled in twin tails with spiky bangs and an ahoge. Her cyan/blue eyes complement her slim teenage frame. She favors the school uniform, dresses, or one-piece swimsuits, often accented with ribbons.

Kayleigh moves through interactions with mysterious unconventionality. She maintains a refined, noble presence that aids integration, while intentionally keeping personal details private. Horoscope reading and astrology are significant skills guiding her decisions; joining the swim club resulted from a horoscope-guided fortune.

Shortly after Chihaya Kisakinomiya's arrival at Seio, Kayleigh formed a connection with the Futari no Elder protagonist. She also befriends Awayuki Reizei, whom she addresses affectionately. Residing in the same dormitory as Kaoruko and others, her enigmatic behavior and astrological interests become familiar to peers.