A story where humanity is close to extinction and aliens try to have them repopulate in any way possible. Basically something like this: https://e-hentai.org/g/1261666/a3424e839a/
It could be interesting if you expand on the idea. For example: -Why do aliens want humans to repopulate? Are they intergalactic trade partners in the future? Are they experimenting further on humans? -Do the aliens have to also protect humans from some other hazard (other aliens, a disease) -What if all men or women have been wiped out? Now the aliens have to re-create sperm/egg somehow (maybe from other species). Does that cause changes in humans (futas, increased libido?)
