In this world, the Birth rate of Male is no more than 100 population. Because mysterious viruses, each time Woman pregnant there's only 0,5% chance of it turn out to be Male, since 5 years ago. You're being frozen five years ago to save the Man with good quality sperm, and now you're awaken by the "Breeding Den" Facility. Where every Woman in this world is fertile, no matter what's the age. It's your choice to love one woman, or build your own harem to avoid extinction.