EDIT: Xeno, you are a much better man than me, I didn't even ask. It's harsh reality from me. XD; You deserve mad respect for asking, though.
As simply FYI, bullying still exists in Japanese high schools (in fact, it's pretty bad, especially for foreign students. You feel lonely now? Culture shock + seclusion for being a foreigner = mega loneliness. It would take a lot more work to get over that then your current issues here in the US). High school is high school wherever you go. The only advantage would be that no one would know about your past, but you'd get that from going to a different school in the US.
Not only that, but entrances exams for universities in Japan are not only expensive (about $250 each) but MURDEROUS to pass. They have all year schools for studying for these exams and you only get to take the exams once a year.
Sorry to burst your bubble, but before you start shelling out money to go all the way to Japan (which is a huge thing, even if you have a fairly good grasp on the language and culture), it's best to consider all options before rashly acting.
Either way, your situation seems like a tough one, and I will be praying.
I'll be honest, high school is a really stupid time in one's life. I really can't think of anyone who looks back at high school and says "Those were the best days of my life." We're all learning about ourselves that age. We change dramatically, our friends often change as well, and we're left thinking, "What the crap is happening?"
Now that you probably dislike me for being negative, I'll try to be a bit less pessimistic in addressing your three troubling circumstances individually.
1. This could be one of a few things. But, it does seem like bullying, in which case, try to swallow your pride and talk to your parents and/or teachers about it. Otherwise, a lot of girls tend to be kind of jerks in high school (speaking as one), since they're insecure. I suggest not playing their game and getting upset by it, but be yourself and be confident in that. And maybe make friends with the guys or something? Unless the issue is the same with them.
But definitely don't give that one girl the time of day. If she insists on trying to dirty your name, she's not even worth your time to talk to.
2. Sorry, call me a cranky old women, but juniors in high school are the worst type. They're not quite seniors, but not still bright eyed and upbeat like freshmen and sophomores.
You are a underclassman, right? Along with your friend? if this is the case, you're friend could just feel that this upperclassman is somehow more interesting in regards to experiencing new things she never has before (emo or hardcore punk music, different way of dressing, etc.). Most likely, you are being viewed as "old news" and someone who's not up with the times because you're not trying these new things as well.
Of course, that's all lies. There's absolutely nothing wrong with you.
But the best thing you can do for your friend is be patient with her. If you want to keep her friendship, you can give her space if she wants it, but just continue being nice to her, ask her to do stuff with you (go see movie or whatever). I'm sure she'll shape up as she grows up a bit more.
3. This is a bit tricky, mostly because you're judging schools by two "minority" schools (private Christian schools are not in a majority). There are about 63,067 public and around 10,653 private schools in the United States. (source:
http://nces.ed.gov/programs/digest/d07/tables/dt07_002.asp?referrer=list ) and you have gone to two privately owned schools (you can't even blame the state's education system for that).
That being said, Christian schools sadly have a bad reputation (even here) for not "being Christian".
Extra bit: Keep your humbleness and confidence in the woman God created you to be, you'll need it. I think this is probably what sparked the comment from your parents. Christians tend to be especially insecure about everything (it's bad enough being a teenager, but all the pressures from going to a "Christian" school can make it even worse), thus it's definitely a possibility that the girls are jealous of you, even for the smallest of reasons. While I sadly don't know you very well, you strike me as someone who has confidence in her she is and you don't constantly worry about whether you're good enough for something. That's a super desirable trait.
Indeed, follow where God leads you, not your heart. That sucks, I know, but from someone who knows loneliness all too well, following your heart will get you into worse trouble. Trust your entire life and self to God and wait for a path to open to you.
Oh goodness, long post. Kudos if you read the whole thing (I'd bake you some cookies too, if I could, since I was a bit harsh). Feel free to PM me if you have any questions. Otherwise, I'll be praying that things will look up for you very soon.