The pentagram (J. gobosei) is a powerful symbol over 5000 years old, primarily associated with Europe and the Middle East. In contemporary Japan the pentagram is closely connected to Abe no Seimei, the Heian-era Onmyodo practitioner popularly known as the ‘Wizard or Master of YinYang‘. Depending on the source, Seimei is credited with having either independently created the pentagram around 1000 years ago or adapted/borrowed it from Daoist charts in currency at that time. Elsewhere I’ve read that the symbol was introduced to Onmyodo through Tantric Buddhism, with the original source going way back to the Pythagoreans. My principal interest in the pentagram is its representation of the five elements/phases (J. gogyo) of Wood, Earth, Water, Fire and Metal. As well as exploring the connection with Seimei, this brings Kampo (a form of traditional Japanese medicine) and fusui (the Japanese way of Feng Shui) into the mix. The challenge to research, describe and interpret the origin, history and symbolism of the pentagram in Japan has been great and is ongoing. The purpose of this exploratory post is to share progress with the intriguing and mysterious puzzle so far and discover if readers can contribute additional pieces.