Ami Eun

She is a senior and friend of Ji-Soo. She is shy and quiet at school, where she often reads yaoi manhwa. She is one of the first to find out about Hae-Young and Jin-Ho's complicated out-of-school relationship. When Jin-Ho learns that she is the one who told Ji-Soo about his situation with Hae-Young, he attempts to confront her. During this face-off she threatens to publicly reveal the relationship, which would be likely to get Jin-Ho suspended and, even worse for him, ruin Hae-Young’s career. She even forces Jin-ho to kneel in front of her without a second thought so as to exert her power over him, and gets pleasure out of it. She seems not to like men in general, and also appears to dislike Jin-ho in particular. It transpires that this was an empty threat on Ami's part, since she herself is also in love with Hae-Young; she even tries to force herself on her teacher, who then turns her down. (Source: Wikipedia)