Seems a lot of authors here post fan-fiction about Japanese animation - far more so than American animation. Is there a correlation?
I think for the most part American animation is less conducive to erotica. Either it is: Aimed at and about children so an obvious no. Is a bit too cartoony/goofy to be erotic except for a niche audience. E.g There is Simpsons porn but I think most people don't really find Marge Simpson hot. No judgement if you do, just commenting on the bell curve! Or the cartoon does have sexy adults in it but is based on other media like comics. Japanese anime have far more examples of films and TV that are aimed at a mature audience and that's leaving aside the actual hentai genre they have going.
I feel that anime has often plots with the main character encountering one or several love interests, the plot being a love story, or a love story being a major side plot of the story. There might also be a difference in the amount of animated content in Japan vs. the US that influences the perception, as well as a difference in themes that would be done with real actors.
I think its more of a natural process, anime/animation, manga/comics, light novel/novel, written fanfiction, erotica, writing your own erotica. With Japan's high pornographic content in each of these categories it is a easier progression to follow. Where with American animation unless it's already an established IP you never really make it past the show. Even if you do you only end up with official releases as the parody market is rather niche besides jokes or one-offs. Sure you can find art with characters from the show but anything with a story is usually nonexistent. So that cuts off a pretty large section of the natural descent to erotica for most American animations. I also think another huge part of the issue is that American animation hasn't really had any good teenage/adult themed works while one could so easily share and produce their own erotica. I mean most of the American animation erotica writing is Marvel and DC works which have been around for almost 100 years. Not to mention that besides those two, the other animation styles aren't very flattering to their characters or give a reason to sexualize them.
Anime and manga is more sexually creative. Japan in general seems less hung up on sexual fantasy, provided you keep it private. American creators seem to write sexual content as if they're scared God is watching them jack it, so all their stuff has this frankly cringe sheen of plausible deniability. Stuff like calling everything a "porno parody", (like "haha, isn't this hilarious? Spiderman and Black Cat fucking? I'm having such a laugh at this parody you guys, I'm not cranking my hog at all!"), or the whole absurd "step-family" thing. The most unironically sexy media you'll find coming out the states are probably Rap music videos and old Frank Frazetta or Boris Vallejo paintings. Anime and manga is just more sexually imaginative and unrestrained. It makes it far easier to cross the boundaries into fantasies beyond just obvious photo or video documentation of sexual acts, which would then lead people to erotic writings. Like, I can't even imagine what this site would be like if not for the influence of anime and manga. And no, I'm not being butthurt over US sexual mores because my story's gotten buried for being about incest, no sir.
