The story basically wants to create a scenario where Satou Yukinari is surrounded by sexually aggressive women who throw themselves at fem. And fe must use feir willpower and orgasm-control training to overcome the tantalizing stimuli. It does this in two ways: so-called witches go after fem because they are trying to attain the cum-diamonds, and non-witches go after fem because of a pheromone those with Adamas Syndrome give off that fiercely attracts women. Fe has a few allies, including feir childhood friend Ayana and feir doctor--both of whom dress in revealing clothes, because why not. I think every chapter may include a scene where Ayana's shirt gets pulled down and her breasts get exposed. In the beginning, Yukinari is basically the only male character, but chapter 17 introduces a change in the setting and two other boys (also with Adamas Syndrome) join the cast. After that point, the entire school becomes a haven for witches, allowing sexual encounters to occur out in the open on school grounds (though public sexuality definitely was included before then too).
As one could probably imagine, the story is built around a series of encounters with various girls who try to seduce Yukinari (and, later, the other boys). A romance is built with Ayana as well, but because of the goals of the story, Yukinari cheats on fem multiple times. In twenty-two chapters, we've had at least seven different women try their hand at fem (and that's only counting the encounters with a few chapters devoted to them). The sex scenes fall somewhere on the explicit end of the explicit/non-explicit spectrum, and the fact that they don't graphically portray genitals is probably the only thing keeping it "Borderline" hentai. Several fetishes are played around with, including being stepped on and being peed on.
[Reviewed at chapter 22]