In his third year of marriage, Yui, the wife who wants to give birth to a child. Every day, I recorded the basic body temperature in my notebook and looked forward to making a child sex on the day of ovulation. However, a tragedy strikes the yui of such happiness. A mysterious masked man suddenly appeared, and with an invincible smile he pushed down his guilt and began to twist the bar which had been erected into a force. He was aiming for an ovulation day to pour his child into her womb. The nightmare danger of repeating until fertilization is started during the day!