The worlds of humans and demons (youkai) have merged, leaving people to stroll down the streets of life as they usually would, while demons wander along the same streets, concealed from sight. Yurine, a presumably youthful lady, and her servant, the Karas (from the Japanese word for "Crow"), have long maintained order and balance between the overlapping realms, preventing demons from interfering with humans' lives. Humans, on the other hand, have grown to forget and mock the presence of demons, and no longer appreciate what a blessing it is to live without terror. Disgusted by this hubris, an elderly Karas abandons the laws he previously maintained in his human form.