Some food for thought:
I suppose my question upon reading your post would be:
Why do you feel it necessary to train in Japan?
Do you feel as though you would be training harder, or in a tone of more serious environment.
Or perhaps you feel as though your training at your local dojo is inadequate or The gaining of new and fresh experience.
(my personal favorite)
You may want to ponder these for your own benefit to ensure your desire comes from a valid (valid only to you of course) mindset.
On the issues of travel,Indeed the last poster was quite right. Make your travel arrangement early.As for income, keep in mind that teaching English is usually available, but note one thing.It is usually long, hard, and you will get paid very little, and worked extra hard, not to mention that you will fall into the general category of being looked down upon secretly by Japanese society for the most part. But hey, it will pay the bills, or most of them, anyway. Bar tending is also available, but also of low status. In most cases a company or school will offer you a contract to work
for about a year or less. If you do decide to go, you will find it probably the most rewarding experience overall, however, it will not be a cake walk by any standards.
I hope this helps!