Unlike a lot of people here, who either hate this story, or love it, I found the plot in this story neutral until chapter 15-17 in where everything started going downhill. There is some redeeming features to this story it, and there is just some plain bad ones.... But here is my opinion.
First of all, this male shoujo protagonist is very different from a normal shoujo "Prince charming". When it comes to "bullying the ones they like", he is not for the faint of heart reader as he is extremely mean to our heroine, sometimes close to the point of killing her and beating her cruely. He bullies her mercilessly and unlike "Hana Yori Dango" (Go check it out if you have not seen it- Much better) he never shares remorse, or gets "better".
Instead, he is an immature bully, which reasons are barely understandable. He is a very warped individual, who's loyalties are not focused on the main girl at all, but towards the individual "who made him this way". The same person who used him as their puppet. It gets much deeper then that, but I digress.
The real reason I kept with this story so long in because of Kyung-hee Goh, a beautiful girl with a very strange sense of fighting, but nevertheless an emotionally strong individual.
I did not realize when I first read this (Maybe because I was blinded by rage and how idiotic it seems not to go to the police after almost getting beaten to death) but as I reread this manhwa a second time, I realized she understood how corrupt the system was. Even if she had gone to the school principle, the responsible bully would not be fairly punished, so she stood her ground. I liked how she was strong, even though physically with normal strength, but I loved her strong will, and her unconventional thinking (although maddening at times)
That is until chapter 15 happened, and things started going downhill....She acted like a lovesick fool. It was amazing, and disappointing. Maybe I will come back to this story in another few years, like from when I first read this manhwa, and maybe not, but I do strongly suggest that you think clearly, asking yourself "Am I open minded enough to not take this so much as a shoujo, as a serious story about bullying? Or will I get offended? (Even if you're sort of hard to offend)"
If you still think you can read this after you answered those questions, then I think you should try it out.