Possibility of a future in Japan

I was born into an Army family of the US, So I've moved around a bit. In Elm. & middle school i went to SEVERAL different schools and we were never pleased with any of them. When my High School career started my mother decided we would stay in one place until graduation, However after the first year or so we found that we didn't like the school but stayed non-the-less. I have been at the top of every school i have gone to and i am now getting ready to start my college life. I've been accept into the college i chose but i am now thinking about moving over seas to Japan. I would be making the move after my first year of college in the states, and i wish to become a surgeon.
I would like to be close(ish) to a city but also with in a decent amount of time to a more country-like area.
I've read the other post on colleges and would like to say that i do not plan on returning to the states to live permantly if i make the move.

Now after all that my questions are:
-Would it be possible for me to transfer from a college in the states to one in Japan?
-I my niece lives with us and will be starting High school that year, how would this affect her?
-what would be some of the colleges to look into?
-If my mother decides to stay in the states what type of living spaces would i need to look into as it would be only me? (or possibly my niece and I?)
-What is the need for medical staff in Japan?
-What types of scholarships are offered in Japan?

Thanks in advance!

-Would it be possible for me to transfer from a college in the states to one in Japan?

Do you speak/read/write the Japanese language? Normally before people get accepted into a Japanese university, they need to study the language full-time for a year or two (intensive) just to be accepted - without this you will not be able to follow the lectures.
Also, medical colleges are difficult to get into, even among Japanese students. So that might be an issue.
Another issue is that medical schools are six-year courses, after which you spend some time working in a hospital for a very limited pay.

-I my niece lives with us and will be starting High school that year, how would this affect her?

I don't even understand your question - if you are thinking about the whole family moving over, there will be a big issue - immigration and visa status.
If you come to Japan to enrol in a language school full-time, then you get Pre-college visa, and if you get accepted in a college, then you are eligible for a Student visa. But your parents and family? None.

ANother thing to note is that even if you made through all that medical education and training, your doctor's license will be only for Japan, so that limits your future move possible, either back to the US or to another country, in case you get dissatisfied here...

Unless your niece get into a regular gov. funded Japanese high school, the private high schools are very expensive. My kids went to ASIJ(American School In Japan)near Tokyo but the tuition fee was way over $20,000/kid plus a lot of extras. Of course, I didn't pay but my company did for 3 kids..

Do you think that after your first year of college you would have the written/spoken Japanese skills to do medical school in Japan? Normally to reach that very high level of Japanese around 3 years intensive study of just the language is necessary. You would need to pass entrance exams that many Japanese students fail, in Japanese.

While I know of a few foreign dermatologists and general practitioners catering mostly to the foreign community in Tokyo for example, I have never heard of a non-Japanese surgeon here and would be very surprised to hear that there are any. If you plan to practice back in the US, as above, you will need to do further study to be certified there.

What visa are you thinking your niece would stay in Japan on to attend high school here? She would not be eligible for a dependent visa as far as I know, and only students in exchange programmes get visas specifically to allow them to go to high school here.