It's nice to hear that someone wants to try and be like a Korean high school student in mannerisms, the type of respect they have towards each other is sometimes really nice to see comparing it to our culture. Naturally, your friends will find you a little odd because it's a completely foreign concept to them! I mean when I was in school a couple of years ago the nature of school was fight to survive, even if it meant leaving a few people down. The Korean culture has a different style to how they act towards and your friends will notice this because in Europe it's just not like that.
For them, it's like trying a new food! You don't really want to try it, but yet, it may be the best food you've ever had! You're just not quite sure about it yet, and you'll get an opinion of whether you want to try it or not eventually, but it'll take a little thinking over.
...Okay, that was probably a bad example.
The only thing I can think of, as selenka95641 said, maybe giving time for your friends to ease in will help them because honestly, if they like you enough (which I'm positive they will be) they'll stick by you no matter what attitude you have towards school life! After all, if you want continue with it, I don't see why you shouldn't because honestly, if it makes you happy, isn't that what counts?