Once upon a time, when youkai still existed, people would occasionally encounter them and tremble in fear. In those days, there was a self-proclaimed genius youkai expert, "Ugetsu Harukaze." Though he called himself a youkai expert, he had only ever seen the cute zashiki warashi that lived in houses... One day, a big mouth appeared on the back of the head of the most popular girl at the brothel! It was a youkai, a two-mouthed woman! The youkai expert rejoiced. After that, the two-mouthed woman left the brothel and started working in a freak show, but...!? This is a collection of the best youkai works by horror author Tsukimori Masako, featuring many other major youkai such as Nurarihyon, Hitotsume Kozo, and Kasha!!