One of the two-second-year prefects of the Black Dogs dormitory, and Kochou's twin sister. She is known as the Engineering expert, with expertise regarding machinery. Despite their small stature, they are actually 14 years old, having skipped grades because of their intellect. However, Teria only joined so that she could be by her sister's side. Teria is shy and timid but is willing to step up to the challenge to help others. As Romio continues to help her, Teria falls in love with him and is pushed by her sister to be more proactive with him.