Ahh... I'm fairly fond of
hitomi.la for hentai, pretty quick direct download without capcha and reasonable interface to find related works in all kinds of languages.
Thanks for recommending Haruki!!! That's exactly what I'm looking for (I think), full length manga (esp. multi-volumes) with a non-sex/romance main plotline that is also intertwined with a lot of sex.
From your suggestion, I grabbed quite a lot of Hidemaru, he's good but the story plot are just filler for the sex. I'm hunting for the rare gems that has story that could stand up even with the sex taken out.
Futa isn't my thing either, you're right... Don Shigeru seems a bit obsessed with futa, now that I survey his works... But I still like Parasiter Miki because there's a smart (almost funny) excuse to give Miki a big warty penis, see it's not a penis at all, but a evil alien parasite which spread its infection but penetrating other woman's orifice, which only happens to look like sexual intercourse. There's also a lot of violence (Miki got a bullet clean thru her head early in Act 2, it's not a spoiler, but there's 7 Acts to go). Also I like the art style that's more 70s. Really a shame Acts 4-9 weren't translated.
I can read Chinese, so lucky to find the Chinese version for all volumes (1-6?) (edit: it seems only half of vol 6 has been translated to Chinese) (re-edit: vol.6 is full translated to Chinese) for Parasite Doctor Suzume. Yes English volume 3 is also missing on hitomi.la