twin succubus sisters fight against each other to get their stepbrother's sperm.
well, you know.. the usual family friendly thing.
and yes the author also made hentai doujin

The twins, Oona and Hooru, are girls who come to the house of Takeuchi Kou, a super-skilled JAV Actor. They looks like a normal girls but they're actually not. In fact, they are succubus who devours human sexual desire. The reason they are in Takeuchi's house is to be with their beloved Takeuchi Kou. However, the succubus can't fall in love with a human because of their species barrier. In order to make this possible, there was a way for a succubus to become a human. That is... To collect "Kintama" that can be obtained through no nuts for a day. In order to get the "Kintama", they pull each other's legs, make each other come, and interfere with each other, and the no horny survival battle begins