This collection of parables written by Issai Chozanshi, an eighteenth-century samurai, is a classic of martial arts literature. The tales are concerned with themes such as perception of conflict, self-transformation, the cultivation of chi (life energy), and understanding yin and yang. These parables seem light and fanciful, but they offer the reader valuable lessons on the fundamental principles of the martial arts. This version, translated by William Scott Wilson, is the first direct translation from the original into English and he captures the tone and essence of the text while also making it accessible and meaningful for a contemporary audience.

The "demon" in the title story refers to the mythical tengu, who guard the secrets of swordsmanship. A swordsman travels to Tengu Mountain and in a series of conversations he 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.
Chozanshi's deep understanding of Taoism, Buddhism, Confucianism, and Shinto, as well as his insight into the central role of chi in the universe, are succinctly explained in William Scott Wilson's fine introduction and extensive endnotes. This is essential reading for anyone who wants to truly understand the philosophical underpinnings of martial arts, and how these principles relate to our existence.