"The tales are concerned with themes such as perception of conflict, self-transformation, the cultivation of chi (life energy), and understanding yin and yang. The "demon" in the title story refers to the mythical tengu, a group of demons who guard the secrets of swordsmanship. A swordsman travels to Tengu Mountain and in a series of conversations learns about mushin (no-mind), strategy, the transformation of chi, and how the path of the sword leads to the understanding of life itself. Some of the fables in the collection-such as "The Mysterious Technique of the Cat"-are iconic."