She hates him. For being arrogant, cold, and just everything a guy shouldn't be. But that's what Kai is--and he gets girls. 

"When we were in grade 8, he kept making fun of my child roundness, laughing at me with his other friends... Throughout the years, I've been seeking different ways to make him go through the humiliation I did. However, that of course, never happened. Because Kai is Kai, and humiliation doesn't seem to exist in his vocabulary, or life."

"Despite running to the principal's office every now and then, all the teachers adored him, always wanting him to perform for the school's special occasions. I never went to a performance once where there was Kai in the show..."