Yukari Kamishiro acts as the vice-homeroom teacher and music instructor for Yūto Ayase's class at Hakujō Academy. Though 23 years old, she consistently proclaims herself "eternally seventeen." Her conduct frequently clashes with typical teacher expectations; she exhibits immature behavior, teases students, and openly discusses inappropriate subjects. This pattern, especially pronounced when she consumes alcohol, leads Yūto to dub her the "sexual harassment teacher" due to her flirtatious advances.

She shares a close friendship with Ruko Ayase, Yūto's older sister, and is a regular visitor to the Ayase home. During these visits, heavy drinking sessions with Ruko often result in disruptive behavior from Yukari, including stripping and propositioning Yūto. Her drunken states typically leave the household in disarray, posing persistent problems for him.

Rumors circulate that she might be the esteemed "Performer of the Sunset," a celebrated musician and Hakujō Academy graduate. While unconfirmed, her recognized musical expertise lends credence to the possibility. Shiina Amamiya, a transfer student, cites this rumored connection to the Performer as her reason for enrolling.

Physically, Yukari possesses blonde hair and green eyes. She stands 163 cm tall with measurements of 89-56-87 and has blood type A. She appears in spin-off media, notably the manga "Kyōhaku Dog's," alongside characters like Yūto and Nobunaga Asakura.