I saw this ten years after it was released, I am not Asian, I am not a teenage girl. So I guess the flaws in this show are impossible not to notice.
1. The F4 are not only jerks with weird hairstyles, they are criminals. They are such bullies at the beginning of the show, it is practically impossible to really believe they are good later on in the series.
2. Jun Pyo in particular is such a big jerk, showing his "love" by constant insults and manhandling.
3. Jan Di starts well, but her character regresses instead of developing.
4. There are some pretty big plot holes there...
5. I really hope schools in Korea aren't like the one in this show, which is plain hell for the weak.
6. Jan Di's family are the worst. They are always trying to get money out of everything. There are one step before prostituting their daughter, if that would mean catching a rich son in law.
But: there is chemistry between the leading couple, Jan Di can be endearing at times, the male lead is pretty attractive in an ugly-handsome way, even with that God awful haircut (apparently he's a very hot name all over East Asia), and the soundtrack is addicting, so I would be lying if I said I didn't enjoy it at all.