有栖川 瑠璃千代

The protagonist's niece, who calls him "Ojisama." An elegant and sheltered young lady who's the great-granddaughter of the school's founder. Very calm and serene, with a polite way of speaking. As it's customary for members of the Arisugawa family to live out on Makishima once they reach a certain age, she lives with the rest of the girls in the dormitory. She dotes on all her friends, and is sort of a motherly figure to them. Her favorite food is instant ramen. [translated from Getchu]