24-jikan Kyousei Hatsujou - Kokumin Bitch-ka Keikaku

The elite social class is using a human manipulation device to alter the bodies of beautiful women into those of females in heat!
This is a story about a country where discrimination betwen the "upper class" and "lower class" has become common sense and socially accepted.

Masayo, a beautiful girl, has been drafted by the country to serve as a "Slut".
A so-called "Slut" is a legal sex slave for an upper class partner.

Oda, who is Masayo's childhood friend, is furious that she got drafted to become a "Slut". With the help of his comrade Hachinan, he has acquired the "Z-system", a nanomachine device that can be used to manipulate humans at will! Thus, his revenge against the upper class begins! His targets are: the women of the arrogant but cowardly upper class!

With Hachinan by his side, Oda puppeteers the actions of the upper class women and alters their memories, but he also violates their bodies until they become pregnant!?

(Source: DLsite)