Yul-yeon was the top student of your class always answering with confidence and having a sense of charisma around him..it was pretty obvious that quite a lot of girls liked hum and those who didn't just didn't seem to care about him..I mean can you blame then he's literally a 6'4 dude with a brawny and masculine physique black hair and brown eyes and porcelain skin  . ..anybody would be head over heels for him although despite all that he was always polite and conservative