Natsuko Kayama ：请不要拔出来。就在我体内射精！- 第1部分

The man is frustrated with himself for being repulsed but attracted to his stepmother, Natsuko. One day, Natsuko gets into a mood with him and ends up having a relationship with him. When Natsuko gets to know the young man, she forgets that she is a wife and a atepmother, and turns into a "woman".