Yin Yang tattoos are very popular all over the world because the idea of yin and Yang has been recognized in any country. The main feature of "Oriental Science" is based on Yin Yang and five elements. The reason why "Oriental Science" has not been recognized internationally is that Westerners can't understand Yin Yang and five elements.
In fact, in western history, the theory of Yin Yang and five elements has also been popular, which has ruled the western ideological circles for 2000 years, that is, the four element theory originated from ancient Greek philosophy. This ideological system is very delicate, ingenious and complex, and its "breadth and depth" is no worse than the theory of Yin-Yang and five elements.