This game/visual novels story was so far fetched and unbelievable I couldn't go past chapter 3... The fact that the protagonists older sisters were pretty much insane perverted role-players trying to corrupt everyone they know including their family was a little unrealistic... Then to have the protagonist just blindly go along with everything, even the choice to say stop when the sister was spanking the other sister, you didn't actually say stop and they just kept going as if you had never said anything at all, it was like that choice didn't really exist... The sisters were pretty much pure evil, not actual sisters that a brother would actually care about, and it felt as if they weren't really related...
So, the plot for this one is very simple, a set of mind controlling sisters just having fun corrupting their family for the hell of it, with no actual love for anyone outside of their little twin world of perversion... There was no depth to the story, and it felt like a twisted porn movie that just wanted to show the reader a bunch of sexual barriers being broken, the end... The plot moved so quick, with your choices making very little difference, that it felt jaded... Didn't feel like a visual novel/game with any sorta substance, just something to get your kicks real quick and move on to another game...
Now, the visuals were decent, but the story is so bad, there is a lack of any real influence on the part of the character you supposedly control, and the plot goes by so quickly, that it ruins everything else...