"Kaigyo" are creatures that walk on land, devour concrete, and destroy buildings.
 
Ten years ago, a young man named Jaytle witnessed his parents being swallowed whole by a kaigyo that shouldn't have been able to eat humans. To seek revenge on the mysterious man who seemed to control the human-eating kaigyo, Jaytle spends his days working to exterminate these creatures. One day, while carrying out his usual extermination work, Jaytle meets a strange woman who eats the raw flesh of the kaigyo, which should have been poisonous...