Tabata Yui♀

Yui is a girl in Takuma's class. She has a self-aggrandizing personality and always has two male henchmen tagging along. She is very rich and often uses formal speech so as to distinguish herself from the "commoners". She is very proud and condescending, but that does not actually mean she is unkind to others. In fact, she gets along quite well with Takuma and the others, with the sole exception of Hayami. She often calls Hayami a "cockroach" and along with her henchmen will bully Hayami relentlessly.

[From Wikipedia]