Greetings, Ray89 san ! Welcome to JREF, the place to learn about Japan and make friends with those who are interested in Japan and/or things Japanese.
I'd firstly like to wish you the best on your dream of moving to Japan; it will be a hard and long road ahead, but it could be very much worth it!! There are a few things that should be taken not of, however:
The ability to speak and to some degree read Japanese will be almost absolutely necessary--unless you were to have a friend/partner or girlfriend of Japanese nationality or who has such ability already who could help/sponsor you.
Having whatever proper credentials you may need for the particular job you'd like to do is absolutely necessary. Of course teaching English, in whatever fashion, is not the only job that non-Japanese can do here, so that may be some comfort--make a firm and fair decision on just what type of work you'd like to do.
Getting a working visa, however, may be the final blow to such a dream. There are others here on the forum who know more about that than I do, so I would suggest that you look around in the 'Japan Practical' fora and see if you can find some information on that--it may be good to do a search and see if you can find any good info in the older posts. I apologize for not being able to say much on that here and now.
One thing that I would suggest also, is that you allow some time to 'age out' a little bit more. Only speaking from experience (and to that degree with limited scope) a few more years under the belt would be to your advantage if you were to come here.
I hope all works out well for you and that you can achieve your dream !! MM