What is the Five Elements Theory (五行説)?

The  five elements theory refers to the five elements of wood, fire, earth, metal, and water. This theory can be used to describe the movement and the relationship between different elements and phenomena in nature.

In the Five elements theory - time, seasons, directions, animals, planets, smells, as well as internal organs - belongs to one of five categories. Yin and Yang theory combines with the Five Elements theory that makes up the foundation of Japanese Shiatsu.