Claire, a vampire who loves to sleep, is banished from her mansion for her laziness, which is unbecoming of a noble family. She is thrown into a strange forest, where she happens to meet the legendary Fenrir, a demonic beast, and takes it as her personal servant just to have a conversation with it. The story of her evolution into a more powerful Blood Fenrir spread, and other demons began to gather to become Claire's dependents. The forest develops into a country where demons live while Claire sleeps, but then humans arrive...