The synopsis looked interesting, but it turned into quite a disappointment.
Story
Pretty much typical hentai show with the main character going and banging his not "blood-related" sisters.
Art
Not much to say pretty much the art was a reason why this wasn't that much enjoyment.
+it was degrading by time-
Sound
Would say the ending theme was more enjoyable than the show and the one song they have sung during the festival wasn't bad.
Voice acting was pretty fair.
Character
The most unappealing main character in hentai ever. This guy was indecisive which sister he actually liked so he banged them both.
Girls were average the art wasn't making them too appealing.
Enjoyment
Only positive thing was that it's 50/50 with a story and sex scenes.
I don't think this is worth your time you can surely find better hentai.