Are there any anime hoặc manga writers that isn't Japanese?

There are plenty of like Korean manga authors....
They call it manhwa I guess but pretty much the same thing lol.

I do not think it would be "Anime" then.
There are collaborations, sure, both in Japan, and with Americans and it is basically the difference in East & West.

Let's say bạn are American and wish to write that style and form... bạn would either go to Nhật Bản hoặc produce your own versions here but they would have to stand on their own, with their own titles under American categories and book names, etc. Nothing prevents someone from incorporating, but if it is American, it would not be an Anime. manga is written different than American comics, so I would guess bạn would have to read legalites of publishing if bạn đăng lên it yourself hoặc ask your publishing house as far as Manga.

Afro Samurai had Japanese collaborators but is American made ( hope i'm understanding the câu hỏi right)

Actually there are several Japanese anime that have had foreign backers to either continue the series hoặc make phim chiếu rạp of.
Trigun, Tiger & Bunny and Panty vớ, thả, còn hàng with Garterbelt as well as the Redline movie were specifically targeted with the western audience in mind.
Which is the only reason Trigun & Tiger & Bunny and the re-vamp of Hellsing (Ultimate) got made.

Arfo Samurai