Not only did this Anime dare to show a female rapist, but a brutal, lesbian rapist. I won't spoil how the protagonist kills her, but that's sure to have caused salt also.
Assuming the commies didn't just cry about the first couple of episodes then move on when it became clear they wouldn't cave.
There's three versions of the anime. Censored, stream version and uncensored. The uncensored is basically porn.