Onmyoudou is a traditional Japanese practice that combines elements of spirituality, astrology, and divination. It originated in the Heian period and is based on the belief in the balance of natural forces, including the five elements: wood, fire, earth, metal, and water. Practitioners, known as onmyouji, use various techniques to predict events and influence outcomes, often relying on the lunar calendar and the principles of yin and yang. The practice involves rituals, talismans, and the use of shikigami, which are spirit familiars that assist in various tasks. Onmyoudou has influenced Japanese culture, including literature, art, and even modern practices like feng shui.