Japan's birthrate has hit an all-time low, and with the survival of the nation at stake, the government has begun to take drastic measures. Thus the National Reproduction Program was created, promising to use an algorithm to pair up "perfect" matches to get married and have kids.

Enter 24-year-old Shinichi Kagawa. Broke and unemployed, he signs up for the National Reproduction Program under false pretenses and is now legally required to marry 28-year-old Shuko Kurokawa, a NEET who's been locked away in her apartment, dreaming of a perfect husband.

For better or for worse, they are now stuck together are forced to make a baby within two years. Things are pretty rocky at first, but as the days pass and they spend more time together, they start to realize that the algorithm may have been right.