Hitozuma Saimin Keikaku - Saimin Gonin de Katei Enman - by Tougenkyo - Adult Sex Game

The protagonist, who is living with his father after his mother died, is a rounin and nigh-NEET. One night, he finally leaves his room after a long time, and see his father doing obscene acts with a beautiful pair of mother and daughter in the bedroom.

The day after, he learns that, because his father is getting remarried, his new wife and her daughter are going to start living together with them.

With suspicion, the protagonist presses his father for answers and he shamelessly reply that he used hypnotism to steal them from his boss.

"It's already too late to change them back. If you have anything to say, then let's see you try snatching them from me."

In order to free the women from his father's evil clutch, an even stronger technique is needed. And so, using hypnotism, he is going to save them.