Why do you want to come live in Japan? What do you foresee yourself doing here to earn a living?
Japan is not an easy country to move to; the immigration policy is rather tight. In most cases you're looking at having either a Japanese spouse or at least a college degree in order to get a visa that would allow you to live and work here. Many years of documentable experience in some professional trades can be substituted for a degree in some circumstances. Essentially, if you are young, don't have a Japanese spouse, college degree, or in-demand professional skills backed up by many years of experience you're S.O.L.
Coming here to attend a language school would do nothing toward qualifying you for a visa to live and work here after your schooling was done.
You can look into a MEXT scholarship, but I wouldn't get my hopes up. I know of no other scholarships, grants, or student loans for which you would be eligible on the Japan side. Perhaps you can talk to a counselor at your nearest public university or community college. Give them a try.