[xzilireight]

If you're a gaijin(foreigner), your gonna get stared at anyway.
I'd wear that hat though.
You are going to be going to one the most homogeneous societies in the world, and the older generations consider young people who dye their hair blond and brown to be "delinquents" (although I understand that that those feelings are subsiding somewhat in the major cities.)
You don't have to scurry around hiding your hair, just know that you WILL get some attention no matter what.