I'm sorry. What you said is absolutely true. It really won't make a difference for you because of your oriental ethnicity; you'll naturally blend in.
I know it is a touchy subject but, truth be told, I guess what I mentioned is more for the Desi, Arab, Black, and other ethnic groups. White, Mestizo and similar groups to be honest doesn't apply "too" much due to the way those groups are portrayed in Japan (look at Japan's fashion industry for a good idea) which is generally positive. Please, anyone, like I said, this is a touchy topic so please do not nitpick, put too much pride in the way, or read too much into my words which may cause you to twist what I am saying. Always remember that Japan is not a international country like UK or the US, so just represent by dressing well and decently, and catch yourself up on good manners in Japan before you attend so you can always leave a great impression. After all, that impression you'll leave behind will benefit you and everyone else in the future as you'll help change more Japanese' mentality towards those groups.
I hope you understand but if you don't understand then you "will" when you finally get here with open eyes.