Kochou Wang

One of the twosecondyear prefects of the Black Dogs dormitory and Terias twin sister. She is known as the Pharmacy expert with expertise regarding medicines. Despite their small stature they are actually 14 years old having skipped grades because of their intellect. Kochou is the more outgoing of the twins. It is hinted she has feelings for Airu Inuzuka and affectionately calls him Achan. Source: Wikipedia