Hi Foxfirety!
Enjoy your trip to Japan!
You might have a bit of difficulty in Japan finding clothes, and depending on what sort of hairstyle you want to maintain.
Actually I find that Japanese hair stylists are some of the best in the world. Not all of course, but a good amount of them. Depending on where you live, I might be able to recommend someone. However their english isnt so great.
Clothes wise, just judge their faces when you walk in the store... if they have a worried shocked look on their faces, maybe their clothes wont fit.
I have a very big busted friend who used to try and squeeze into teeshirts, and the sales girls would shriek!
You could always fly over to Seoul, there are places catering for African Americans here. Clothes wise, im not sure about hair though....
So yeah... what style do you have?