South Korea is the country with most "mystical" flag: Taegeuk, Yin and Yang, and the four elements...
Have you ever paid any attention to the flag of South Korea?
Take a look on the Wikipedia article about it:
Flag of South Korea
The flag of South Korea, or Taegeukgi (also spelled Taegukgi in convention) has three parts: a white background; a red and blue taegeuk (also known as Taiji and Yinyang) in the center; and four black trigrams, one in each corner of the flag. These trigrams are carried over from the eight trigrams (Ba gua), which are of Daoist origin. Taiji (philosophy), Trigrams and Taoism are parts of the Chinese Culture which influences Korea throughout the history.
Dude, they have the taegeuk, with the Yin-yang principle, in their flag!!
In Chinese philosophy, the concept of Yin-Yang, which is often referred to in the West as "yin and yang," literally meaning "shadow and light," is used to describe how polar opposites or seemingly contrary forces are interconnected and interdependent in the natural world, and how they give rise to each other in turn in relation to each other.
Taegeuk refers to the ultimate reality from which all things and values originate and is the Korean pronunciation of the Chinese characters (i.e. Hanja) for Taiji.
The taegeuk design was also used to drive off evil spirits. In the Goryeo and Joseon dynasties, the design was later used to represent Korean taoism and to express the hope for harmony of um and yang to enable the people to live happy lives with good government.[3] The blue and red swirling semicircles of the Taegeuk pattern have existed since ancient times.[4]