I think allhailhata and sarasi have answered your questions regarding to being a nurse in Japan, so I would like to give you a few advice if you want to come to Canada.
I would say, it's a lot easier for you to be a nurse in Canada than in Japan, except that I don't know if nursing school accepts international students. (I know medical school does not accept international students at all, and law school as well? I am a computer science student so I never care about this) If you can get your way to come to Canada, you can go to either nursing school in universities, or colleges which provide nursing program (such as St Lawrence College in Kingston, or... sorry please find it yourself... I have a friend who studies nursing in St Lawrence now, that's why I know it). Canada is in shortage of nurses, therefore I think Canada welcomes you more than Japan does (totally no offense, I mean it).
Most Canadians are friendly and open-minded. You know what, same-sex marriage is even granted and recognized in Canada. So you will be more comfortable living in here.
Good luck and all the best.
It seems that my question in the other thread is ignored or no one can answer it for me, I will ask it here again. How's the situation about medical computing in Japan? Is there any university doing research and providing undergraduate/postgraduate study on medical computing and biotechnology? And is there any company developing this? (I know Toshiba medical is doing something related but I don't think its base is in Japan)
Medical computing is a newly developed science which includes computer-assisted surgery, medical image processing and clinical used software... etc.