hello bakr_pathologist, and congrats!
I wanted to answer you on PM you send, but I guess it is better here, so other people who are interested in it can see.
I actually can't help you much. Really do not know how you can prepare. I was asked something like this... first I introduced myself. they asked WHY I want to study in Japan. I think that is most important question, and you'll have to explain it really detailed. then about study program, about Japan in general, about my previous trip to Japan (study trip for Japanese students), and what I've learned from it. What are my plans after (big one too, I believe, at least for me was), a little bit about me and my country, etc.
overall, nice and pleasant conversation (but I was very nervous, of course)
It's been almost year now from that, so I forgot a bit. but those are main questions, I bet.
Now I have question for all of applicants.... Here, in Bosnia, application procedure for this year finished just yesterday. How come that you already have tests and interviews? :?
Thanks for the sharing. So you are now in Japan studying for your postgraduate?
I guess different country will have different time schedule for the application, language test, and interview. Some country might be earlier, some might be later.