How did the yin-yang technique come into being?

Yin and Yang are very popular incantations in ancient Japan. At that time, people often invited Yin and Yang teachers to pray and exorcise ghosts for them. Until now, scrolls about Yin He still exist in some ancient temples.

In historical facts, Yin-Yang Daoism takes astronomy, calendar and missing engravings as its main responsibilities, and divination and exorcism go hand in hand. At the same time, he is also a scientist and technician. However, in folklore, it is often misinformed as a user of spells. Take Abe Harumi's Twelve Gods as an example. It refers to the twelve gods in China's six-rent law, which was used for divination and calculation, but was misinformed by the people as the inscrutable twelve gods to serve. Today, although Yin-Yang Taoism is talked about by people because of Baku Yumemakura's best-selling book Yin-Yang Shi, people's correct understanding of Yin-Yang Taoism needs to be strengthened.