Kashii, Yui

香椎結衣

Junichi's classmate and class representative, she has long dark hair and reddish eyes. Junichi's friends view her as the school's madonna—smart and beautiful, like a character from a manga or video game—though she has a modest chest size compared to the other girls. She has known Jun since middle school and initially acts very friendly and nice around him. She secretly dresses up as BoA, a blonde-haired (red-haired in the anime) twin-tailed idol who does live streams on the internet. She is upset that Junichi, whom she considers her number-one servant because he helped carry boxes for her or picked up her eraser, does not fawn over her like an obedient pet since he is with Yukana. She tries to fix this by pulling him aside and asking him to dump Yukana and go out with her. When Jun refuses, she gets very angry and threatens him until Ranko saves him by threatening to reveal her online identity. She becomes more attracted to Junichi beyond just wanting him to be her pet, and eventually confesses to him, only to be rejected. She then strives to be his second girlfriend in a harem, even following the two of them to university.