Based on the CG collections by Yorokobi no Kuni (ヨロコビの国).

Episode 1
Invited by friends for a date together. Looks like something strange, there is one woman who looks like less comfortable. Feel like I've met, maybe met often. Unwittingly the woman is my own sister! In the same karaoke room, we play King Game. Then, what will happen to me with my sister later?

Episode 2
Have a sister who is easily angry it's difficult, just want to say something spelled pervert. But one day, suddenly there was a hole in the wall of my room, which happened to be adjacent to my sister's room. Because of her angry nature, I am not sure this hole is her deed. When i peek, it turns out my sister was masturbating and immediately there is a live onahole that welcomes my penis to enter.

(Source: Translated and Edited from Nekopoi)