I think what
princessmarisa is talking about is your perspection of Japan when you haven't been there yet.
When I was in high school, I dreamed sooo much to go and live in Japan. Yes, I like mangas and japanese food, but the culture and the country itself always fascinated me. I'd started learning the language and I loved it too. I talked to people online, met others in my city, and a lot of people told me "You should go for a trip in Japan, anywhere you want to stay, go visit, have a look, try it out first!". Which I did.
And it's a good thing, because I realized in the end, my whole perspection and idea that was Japan and Tokyo,
completely changed. I realized it wasn't what it appeared to be in my head. Wasn't all the awesomeness that I thought it was (don't get me wrong, Japan's still awesome in my eyes).
All that to say, if I hadn't visited Japan and moved there like you seem to be planning/wanting to do, I would have ended up regretting it and being pretty miserable. I love Japan, it's an amazing place to go out to on trips and visit. But I would NEVER live there. But that's just me and my opinion.
At this point in your life though, I think your #1 priority would be to finish school. If you're mind's set NOT to do that, then find a job and start saving your money to go visit Japan for a week or two and see if you really love it that much. But you won't be able to teach english overseas without a bachelor's degree.
Sorry.
Anyway. This is just my opinion. It's really up to you to decide what you want/will be doing. Best of luck~