@KatoShuu NGNL's author real name is Thiago Furukawa Lucas, and their parents are also brazilians, descendents of japanese overseas immigrants.
https://myanimelist.net/people/4212/Yuu_Kamiya
His face is pretty much brazilian, and in a interview he said he suffered so much bullying that he had to abandon middle school. Probably this was the reason for his later sucess (Rei Kiriyama feelings, lol)
There are lots of professional gaijin mangakas, but it is rare for them to be responsible for very famous works.
One example of another brazilian, without any japanese roots, is Angelo Mokutan:
https://ameblo.jp/a-mokutan/
Author of this manga:
https://www.amazon.co.jp/%E3%83%AC%E3%82%AA%E3%83%8E%E3%83%BC%E3%83%A9%E3%81%AE%E7%8C%9B%E7%8D%A3%E5%88%91-%E3%82%B3%E3%83%9F%E3%83%83%E3%82%AF%E3%82%B8%E3%83%B3%E3%82%AC%E3%82%A4-%E3%83%A2%E3%82%AF%E3%82%BF%E3%83%B3%E3%83%BB%E3%82%A2%E3%83%B3%E3%82%B8%E3%82%A7%E3%83%AD/dp/4866691212
"Leonora's ferocious punishment"