[ACN]

Hi

I think you need to be a native-english speaker to become an English teacher, or lived 12years in a english speaking county.

Yes you will need to have a Bachelor degree to get a work visa.
I would say you sould get a bachelor degree in your home-county in something you love to do for the rest of your life. Then try to find a job in japan.
Maybe take a holiday trip to japan and search for some possible jobs.

Anyway, others can tell you more about this then me.
Good luck.