Юкиджи Кацура

Хинагику's older sister, a history teacher at the Hakuō Academy where Nagi, Hayate, Hinagiku and others attend, is irresponsible and lazy, a big drinker, and greedy for money, yet she is a good teacher and her students love her. She often borrows money from Hinagiku but rarely pays it back. When she and her sister were abandoned by their parents as children, the girls were burdened with a huge debt, which she later repaid using her "special methods".