Haruna is the eldest daughter of the Kizami family and Yuuya's older sister. She's an honour student with excellent grades and renowned for her intelligence and beauty. Both male and female students look up to her. She's very disciplined and strict with herself and expects the same from others. She doesn't hesitate to scold her classmates if they act sloppily or get into fights.

She acts the same way with her family and doesn't tolerate when her brothers act dishonestly. She's particularly mindful of Yuuya and is always making sure that he doesn't do any misdeeds.