A month ago, the demons broke the seal and returned to the human world, hiding in a cave near the village.
For the peace of the village, Erin and Marie's husbands decided to kill the demons and set out for the cave.
But they didn't come back.
The village mayor and other villagers decided that they were dead and
decided to keep the village blood alive by giving Erin and Marie a child in the village before the demons attacked.
Erin, who does not want to believe that her husband and friends were killed by the demons,
trained herself to capture the cave and continued to search for them, killing the demons on behalf of her husband.
Until she's conceived by another man...