This review will also cover the Accelerando, Stretta, and Ultimatum Sera series (also created by Yuki Seto).
But before I begin, I must VEHEMENTLY CURSE OUT at the bastard(s) over at JapanAnime, the bastard(s) over at NuTech, and those dishonorable "illegal downloaders" who refuse to buy whatever they actually LIKED watching. If it weren't for them, we would've gotten these type of hentai goodies uncensored (and dubbed).
Now with that out of the way...
Yuki Seto's h-manga series turned adult anime is one of the best out. The anime follows the manga storylines; yet strays from them with original stories and adventures of the established couples.
But what the series is REALLY known for is the "internal money shots." The live-action adult video people tried their hardest to replicate this. But this is an anime-only feat. The Stringendo series (along with Pixilith and Milky to a certain extent) had taken it and perfected it.
The world Yuki Seto created for this adult anime steampunk-esque and quite impressive. Something out of Last Exile or Windvalley's Nausicaa, sort of.
And while the stories focus on HOT SEX orz between the hot chicks and the guys they meet; half of the series is spent on either the comical or the tragic. There were a few "post-scenes" I'm not happy with (being the casual / normal guy I am).
I wanna recommend this series to everybody starting out with adult anime. This, and the Discipline and Bible Black series second.