Yukari Kamishiro is the vice-homeroom teacher for Yūto Ayase's class at Hakujō Academy, teaching music. Twenty-three years old, she frequently declares herself "eternally seventeen." She shares a close friendship with Ruko Ayase, Yūto's sister, and often visits their home to drink. Her behavior becomes increasingly uninhibited when intoxicated, including stripping and making passes at Yūto, who calls her the "sexual harassment teacher." She constantly smiles and enjoys teasing troublesome students.

Unmarried and openly seeking a boyfriend, she exhibits a permissive, flirtatious nature, showing little hesitation discussing intimate topics or flaunting her appearance. Her conduct often lacks expected educator formality, contributing to an immature image compared to her students. She has blonde hair, green eyes, wears glasses, stands 1.63 meters tall, and has measurements of 89-56-87 cm.

Hints suggest she may be a distinguished alumna of Hakujō Academy, rumored to be the famed "Performer of the Sunset" from the music world. This reputation indirectly influences characters like Shiina Amamiya, who transfers to Hakujō partly due to rumors of this teacher's presence. Her role remains consistent throughout the series, including the OVA finale, without significant development or alteration to her core traits or backstory.