Try the Masquerade series.
Includes Gosenzo San'e (4 episodes 1998), his sequel Zoku Gosenzo San'e, (4 episodes 2000) and a spin-off, Anata dake konbanwa (5 episodes 2009), all OVA taken from manga.
A series with an articulated plot, so as to seem a "normal" series, in which sex is not the substance of the story but an element of the narration, often played more on the situations than on the mechanics of the act.
A dramatic plot for the first two series, although with some humorous traits and an occasional and light use of the "deformed stile".
More hentai but also light and comic the third series, in a scholastic context.
In English there are several torrents on Subekei and for the third series the DDL from EcchiOujisama's site.
Another notable series is "Hyakki - The Secret of Devil's Island". 3 episodes whit a particular genre BDSM, mostly consensual, and a general atmosphere of mystery.
This is a bit more difficult to find but it's on a vital torrent of a large archive (Hentai Collection Sorted - K.B.).
Well, there are others too.
Maybe I can open a new argument in the section of the English language animes.[DOUBLEPOST=1544318415][/DOUBLEPOST]For now, I add "Shocking Pink Girl Momoko" which is a sexy softcore comedy of 1990, romantic and funny, that goes beyond the limits of the classic comedy ecchi, with a freedom typical of the animes of the time, but it is hard to categorize as hentai, with the story of a sweet aspiring actress who lives her sexuality serenely and sees herself as the Japanese Marilyn Monroe;
It's actually a love story, with sex of course, but the emphasis is on feelings and the development of relationships between Momoko and Kentaro.
It's only two episodes but with 40 minutes each one.
I personally found a good release on a Japanese magnetlink and republished it on Subekei, like Kitsune, and publishing also my sub in 4 languages.
It also existed in German, I believe, but I could not find it.
If you succeed ...
To be seen!