Cultural odds and ends

Normally the Japanzine is crap but this month's issue, about weird Japanese fetishes, was interesting. The artist Hokusai (1760-1849), most famous for his woodblock prints of Mt. Fuji and for every piece of Japanese art that you can identify, was also (maybe) the first artist to depict tentacle porn. As far as I know tentacle porn is endemic to Japan, but I find it extremely interesting that the first example of this is found in The Dream of the Fisherman's Wife (third picture down), which is almost 200 years old. I've seen enough anime and manga to know that interest in monsters and creatures with tentacles having sex with, and often raping, women is alive and well.

What's up with that?