Kazuki receives a letter out of the blue telling him that he has been chosen for the Men's Birth Program. To fight the low birth rate, this program allows men with good genes who had a certain inoculation as a child to become pregnant. Not only that, if he doesn't become pregnant within 24 hours, his "thing" will fall off! He asks two guys he knows to come over, they have sex, and... Will Kazuki choose to become pregnant!? Or will he stop being a man!?