Aoi Yusa

Novel debut: Volume 7

She is the student council treasurer and also a classmate of Sena, who always takes 2nd place in exams since beginning of high school. Aoi looks way younger than she actually is, having small body and being quite short. She has spiky hair with red tinge. Fitting her appearance, she has rather childish or better called "strange" personality, and shares rivarly (one-sided) with Sena, whom she regards as a perfect person. She also has rather strange taste in dress and looks calling Kodaka "super cool", and "very fashionable".

(Source: Boku wa Tomodachi ga Sukunai Wikia)