Female adventurer Sumire joins the group of the current hero, Laris, but is expelled due to her lack of ability. While wallowing in despair, Sumire learns that Laris and his group have gone missing after being attacked by monsters, and is simultaneously attacked and injured herself. Facing certain death, Sumire resorts to a forbidden technique taught to her by her former companions: the "Insect Devouring Technique," which allows her to absorb the power of humans and monsters and transform it into her own. With this extraordinary power that grows stronger through interaction, Sumire vows revenge against the demons! Using her newfound power, Sumire pursues the monsters that caused Laris and his group's disappearance. What fate awaits her as she succumbs to her desires and desires for power?!