In my experience, they are cool as f*ck. Helped me when I got lost in Shinjuku, all the workers were pleasant and patient with me, got my tatt by a Yakuza artist, when I'm in the club, the women are BAD and hella approachable. I have only had pleasant experiences whenever I go to Japan.
But the caveat is that I speak Japanese... if you don't, YMMV. I would recommend sticking to the areas that are known for a military presence if you can't speak Japanese, like Yokosuka in Kanagawa (this is a little outside of Tokyo. Maybe a 35 minute train ride?) At least there, they are used to seeing foreigners, most importantly negroes like us.
Might not want to be where you want to look for a female to date, due to them being Black foreigner crazed and hoes, but if you looking to get your dikk wet, that's EXACTLY where you want to be