And everything in between
Literally: shadow / yin – sunlight / yang – five – go
Alternately: The dual principles of yin and yang, and the five elements (wood, fire, earth, metal, and water), that supposedly form and regulate the world we live in. The building blocks of East Asian cosmology.
Notes: Reportedly imported from China some time in the 6th century CE, this concept – also known as 陰陽五行説, where 説 (setsu) is something like “theory” – flourished in the Heian court and continues to exert influence in Japanese culture even to the present day, when it has been officially declared a mere superstition.
The 陰陽 in this phrase may also be pronounced on’you or onmyou without any change in meaning. However, pronouncing 行 as kou or gou is considered an error