在可持续发展的推动下，人口零增长将成为未来社会的重要目标。yeyese

　　In the not too distant future, a very smoggy and overpopulated Earth government makes it illegal to have children for a generation. One couple, unsatisfied with their substitute robot baby, breaks the rules and gets in a lot of trouble. (Z.P.G. stands for Zero Population Growth).