Yukari Kamishiro

Yukari is the vice-homeroom teacher to Yūto's class and is an old friend of Ruko. She is constantly smiling, though she enjoys teasing trouble makers. She likes spending a lot of time over at the Ayase house, and is unmarried though wants a boyfriend. At school, she is in charge of teaching music. She is twenty-three years old, though refers to herself as "eternally seventeen".

(Source: Wikipedia)