I'd say Sterilizing, and isolation from the normal society (maybe just through a mark on the arm or something, (something showing they are different)), I think that the boy and the girl will find each other in love but not able to express it well before near the ending.
Oh btw, I love your idea :)
I have a story at thecomplete opposite end of the spectrum.
Many years ago my sister bought a hi-fi system from Dixons (remember them?). Well it broke and I said I would return it to the store. The system was boxed and off I went, all set for verbal fistycuffs.
I walked into the store and...