So I just discovered this manga, and I'm thoroughly enjoying it.

It's set in a French revolutionary future where there are no men due to a virus that targets Y chromosomes, making it impossible for male babies to be born.

~This makes sense, if you think about it. The Y chromosome is notoriously weak, which means that it's more likely for a male baby to miscarriage than a female baby. Evolution has balanced the problem by making Y chromosome sperm more numerous, so that it's more likely for men to be born. That's why there are more men in this world than women - with the advancements in medicine, it's less likely that any baby will miscarriage than ever before, letting more of those male babies into the world.~

Anyway, to compensate for the lack of men, the world government has decided that women should be divided into two genders - Adams and Eves. Adams are raised to become the soldiers and workers, being taught the martial arts and chivalry, and are referred to using masculine pronouns (he, him, etc.). Eves are taught to be the housewives and homemakers, and are referred to using feminine pronouns (she, her, etc.)

Adam and Eves are allowed to pair off, having children through a process of artificial insemination. While not illegal, two Adams or two Eves pairing off is highly frowned upon by society.

Enter Koshiro Aoi, a product of two Eves. He begins life in an academy for the upper echelon of society, and is determined to run the school. Yet a freak accident has left him a month behind the other students. On his first day, Aoi gets lost attempting to find his classroom, and, by chance, is happened upon by Sakura. As an etoile of the school, he is Aoi's sworn enemy. Yet what will fate decide?