Melphiera Marchalrayd, the daughter of a count, dedicates her time to researching the culinary possibilities of monster meat—a peculiar endeavor started by her late mother. By teaching the people of the Marchalrayd lands to prepare such exotic ingredients, Melphiera hopes to help stave off famine. Unfortunately, her unique tastes and intimate knowledge of monsters have led to her social isolation: few nobles interact with her willingly, disdainfully calling her the "Voracious Villainess."

When a monster attack erupts at a royal banquet—where Melphiera has been sent to find a husband—Aristide Rogier du Galbraith, the younger brother of the crown prince, leaps to her aid. Due to his terrifying skill in slaying monsters, Aristide has earned the title of "Blood-Man Duke." Charmed by Melphiera's fearlessness and intriguing culinary prowess, Aristide soon declares his intent to propose.

Together, Melphiera and Aristide, high society's most eccentric couple, strive to see beyond the cruel rumors and encourage each other's fascination with monsters and the art of preparing them.