The father repeatedly commits incestuous acts as a form of sex education for his daughters. The sisters accept it and are trained... One day, the younger sister is being trained for sex for the first time, and the older sister desires their father's dick. The mother witnesses them all entangled with the father, and tries to stop them. Her frustration at the rut of sex explodes and she becomes aroused. Finally, the whole family is entangled in a loving incestuous act...!?