Yui Kashii

Date of birth: June 17th, 1999
Height: 5ft 3in/160cm
Weight: 107lb/48kg

Junichi's classmate and class representative, who has long dark hair and reddish eyes. Junichi's friends regard her as the school's madonna, smart and beautiful, like a character from a manga or a video game, but with 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 a blonde-haired (red hair in the anime) twin-tailed idol named BoA who does live streams on the internet. She is upset that Junichi, whom she deems her number-one servant because he had helped carry boxes for her or picked up her eraser, does not fawn over her like an obedient pet because he is with Yukana. She tries to remedy that 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 net identity. She becomes more attracted to Junichi beyond just wanting him to be her pet, and eventually confesses to Junichi and is rejected. She then strives to be his second girlfriend as in a harem, even following the two to university.

(Source: Wikipedia)