This final thesis is about Japanese folklore. It provides examples from shugendō, a mountain based folk religion, and from the beliefs and stories about yōkai, Japanese ghosts. The idea of folklore and folk studies is explained, with a focus on Japanese folk studies. In this field of study, there is a word about the founder of Japanese folk studies, Yanagita Kunio, who is discussed in a couple of chapters. The goal of this thesis is to show the main characteristics of Japanese folklore and to delve in the psychology behind the folk practices. Therefore the themes are ghosts and ascetic practices whose purpose is to attain mystical powers. Through these examples, the thesis focuses on the very basics of folklore that remain unchanged throughout the centuries of Japanese history. They are, in fact, more of an all-world nature, and in Japan they are but a regional variant. At the same time they are universal and individual, therefore they are important for the understanding of human behavior, that is the essence of man.