Jokes apart, Ore no Monogatari! is one of my favorite romance manga, the MC isn't the perfect handsome man that gets all the girls, instead, that person is his childhood friend, and the MC always lived by his shadow. Until Yamato comes! When I read:
That was the first thing I thought.
Yamato's fluid is more potent than any aphrodisiac out there. From Maji to Maji A3 all of em become obsessed with him after they got taste of it, no matter your deretribe is and your age. Even Haou,Azumi n Margit want another piece of Yamato after 'that'.