I'm looking for some ero manga/anime where the main character possesses some kind of pheromone or "potion" that drives women crazy. Stuff where the guy's not a gorgeous fellow that the girls swoon for, but something about this pheromone will turn any girl on so much that they can't resist. An engineered pheromone that the guy can spray at a girl, like in the Oni Chichi hentai anime, is OK, but mainly looking for stuff where the guy has no control.

A great example is Daisuki Daisuke from Yuuki's manga Kare to Kanojo no Jijou. The guy was a total geek, and none of the girls liked him, but if he got excited he produced a smell that had girls desperate enough to grab him and demand immediate satisfaction. That one had a bonus since the guy had been the first boy at a former girls' school.

The best of this type is stuff where the guy's not particularly attractive, so the girls keep trying to figure out why they want him so bad or what happened to them.