Having lost both her parents in a fire at the age of fifteen, Sae was adopted by her uncle and treated like a slave. When a marriage proposal arrives for her younger sister, Chiyo, Sae is forced to take her place. The reason for this substitution is that the prospective fiance is a beastman, a race rumored to devour humans. However, upon meeting her future husband, the white wolf Souhaku, Sae finds him quite different from the man-eating beast she had anticipated...