So...when someone adress nobody in paticular a fake accent its racist how exactly? No names were called in what I said so I fail to see your agument, I do see your admission to being a racist tho 
Perhaps racist is too strong of a word here...how about "stereotyping"?
As for my "racist" jokes with friends, I can do that because I know the person I'm talking to, because I know they won't be offended.
You on the other hand, are making stereotypical comments about a group of people you never met (unless you're friends with all of Japan), and to some one who don't know you, it's offensive.
But whatever, I'm sure you'll continue to do it anyways because hey, it's the Internet. Like I said, I could care less. Ta Ta, toodle doo.