Yuki is a young woman fascinated by beasts that emerge after dark and feed on human flesh. They strike terror in the heart of every normal person. However, what exactly they are and what they look like remain shrouded in mystery. Of course, except for the organization "protecting" humanity from them. Following in her father's footsteps, Yuki has always dreamed of working with this organization. However, when one day she saw the beast with her own eyes, her plans changed...