Lol. I wonder how the real Kazuyoshi Ishii would react if he found out about this? And I don't mean the author of this manga, there is an actual organization called K-1 that was founded by a Kazuyoshi Ishii.
https://en.wikipedia.org/wiki/Kazuyoshi_Ishii
"so was the author a retarded racist or misunderstood and people overreacted? I can't understand"
I think if it was to the point that the VA's of the four leads resigned in protest, I don't think there was a misunderstanding.