I absolutely adored the premise of this yaoi, the execution? Not as much.
Into every generation is born a Demon King. For each Demon King, there is a hero who must conquer him. This is almost exactly the same set-up as the anime Hataraku Maō-sama! / Devil is a Part-Timer, which I likewise adored. Only, in this version Maou (the name literally means ‘devil’) is a kind of hapless storekeeper who doesn’t really want the power to randomly enslave delinquents (it’s awkward to have people falling at your feet all day long.) The hero, Kamiko, is likewise atypical for what you’re expecting of a hero. In fact, when we first met him, it’s because he’s bought the building Maou’s storefront is in and forcibly evicts him.
The hero is kind of an a$$hole.
Not only is he a jerk, but he’s a little bit shady. At one point, Kamiko confesses that he went into the family business (and, yes, he means that in the yakuza sense) because he really just wanted to break-in to people’s houses and knock over vases (like a cat?). Maou, of course, is like, “Dude! That’s not cool.”
Because, somehow, in these stories the devil is always kind of decent human being.
In Datte Maou-sama wa Kare ga Kirai all of this is really just background for Maou and Kamiko to have a lot of sex–because, you see whomever dominates the other one is the victor in this spiritual/world-domination power play. Maou keeps trying to top, but he’s pretty helpless to Kamiko’s advances.
This is listed under the tag “dubious consent” on Baka-Updates, and I suppose you can imagine it that way since Maou does say ‘no’ and keeps telling Kamiko he’s a pervert and not to touch him ‘there’–but this feels more silly to me than rape-y. I suspect milage may vary, however.
For me, this was too tame. (Also the early pages of the manga are badly translated, so it’s probably okay to skim them to get to the sexy-times.)