Right after his graduation, our hero loses both his house and his possessions. Then, he is spirited away by a pair of sisters he has never seen before. Though bewildered and confused, he agrees to move in with them, only to be pestered by the younger sister, Yuina, who insists on having his baby. Things only get worse as the other sister, Koeko, decides she wants to be the mother of his child as well. And so begins the hero's new life, a life of sweet, depraved cohabitation with the two sisters.