Year 2223, Kyoto Prefecture. The human population is decreasing due to the bird-like creatures called "Harpy," which feed on humans, plunging the world into a crisis of poverty. Sokaishōgo, who loves gambling, the adult industry, and food, is one of the members of the "Executioners," a unit tasked with exterminating the Harpies. While skipping work as usual, Sokaishōgo is suddenly attacked by a large flock of Harpies. It seems like Sokaishōgo is about to be devoured by humanity's natural enemy, but there is a "secret" hidden within Sokaishōgo's body—? This is the opening of an unconventional gluttonous dark fantasy.