Ai wa Sekai o Sukuu no ka!?

In a world were the number of women being born is decreasing and it's now mainly a male society, scientists are trying to figure out a way to bring back humanity and fix this virus. A famous, upper class, bright, young and handsome scientist named Mikoshiba has come to the lower class area in order to help their research due to his interest in a cute, naive but average scientist named Niino who dreams of saving the world.