After losing her fiancé, Youji, in a mountain climbing accident, Mai is determined to have his child. With steely resolve, she turns to his colleagues in genetic research for assistance. However, the project demands a staggering sum of money... To fund the endeavor, Mai accepts a highly unusual position: that of a DNA Hunter. Their task is to secure semen samples for women who wish to bear children by specific men—by any means necessary! (Quite the occupation!) But before Mai can join this exclusive group, she must first pass a trial: select a random stranger and obtain his semen. Can she succeed? Will she manage to pass the test? Can she sleep with other men and become a DNA Hunter to preserve her dream of having Youji's baby...?