Here's the goods, for those interested. Even the non-H doujins have them in a lewd relationship, though the rest don't show it.
@mikegnesium
He had to say something, and aside from shoujo or straight shota, any given mangaka is generally more likely to be male than female. It's an especially understandable assumption for people in the West, since the western women we're used to are more likely to take a different approach to male-majority media (i.e. bitching about "male fantasy", attractiveness, and so on). Though even with everything in mind it can still be surprising just who does what; I remember seeing one rather brutal ero-guro manga involving cockroaches, where the author's afterword mentioned having been inspired by a painful uterine medical procedure she herself had undergone.
All that said, I think Itou Hachi is indeed female, but I haven't seen any proof either way.