Miyuki Rokujou

Miyuki is the student council president of Miator, Miyuki tries her best at doing her job in keeping everything in line. Often, when Shizuma is neglecting her duties as the Etoile, she gets annoyed at her and scolds her about it, which makes them seem more like a mother-child pair than as classmates. The two have been rooming together since they arrived at Miator years earlier, but their "parent-child" roles were initially reversed. Nevertheless, the two seem to be friends and have considerable knowledge of and insight into each other. After the death of Kaori Sakuragi, Miyuki became Shizuma's assistant and has remained a confidante of some importance.

(Source: Wikipedia)