Ommyodo, which owes its origin to ancient Chinese natural philosophical theory and Inyo-gogyo-shiso theory (the way of Yin and Yang, combined with the Taoist theory of the five elements), is a system of natural science and the art of spell-casting that uniquely developed in Japan.
陰陽道（おんみょうどう）は、古代の中国で生まれた自然哲学思想、陰陽五行思想を起源として日本で独自の発展を遂げた自然科学と呪術の体系。