A pretty solid 1st episode. Easily recommendable to anyone what with it being vanilla and generally lighthearted as well. It's worth checking out if you're into succubi, vanilla, and/or incest with an imouto that's not petite, which is always welcome to me.
* The art and animation. The animation is pretty clean all throughout and consistently good. The scenes were animated pretty well even if they're really not much, what with the show being vanilla and all, but they're still pretty good.
* The plot. I've "read" the source material for this last year and most of the stuff i've wondered about the plot
only made sense to me now after seeing the hentai anime adaptation, and surprisingly it's pretty good and the mystery factor is pretty intriguing too.
* The character designs. I guess it's not the best out there since the 2(or should I say 3) main girls, the MCs imouto and his female classmate, are pretty standard looking for the most part. It's not until they transform into their succubi state that i can really say that their design was really well done.
* Hmmmm. Can't really think of any at this time.
Things that might turn you off:
I'll say this one was a pretty solid release so far. Episode 1 ends on a pretty nice cliffhanger that just makes thing a bit more interesting and prevents you from getting bored of the seemingly uber-generic plot, but i'm not going to expect too much of it. The sexy succubi designs are enough to keep me glued to my seat even if i'm not the biggest fan of vanilla. Again, easily recommendable to anyone who watches hentai, or maybe even as a first and i'd say it's worth checking out for any of the veteran watchers out there, even if it is pretty vanilla.