Miso is thought to have been introduced to Japan from China around 1,300 years ago.
It is said to have originated from “shou” or “hishio,” soybeans preserved with salt in ancient China. At some point, the substance that emerged before completion of the shou aging process was found to have a pleasant taste. It was this substance that eventually evolved into a foodstuff all its own – the food we now call miso. It has been suggested that “miso” comes from the word “mishou” (the Chinese characters for which mean “not yet shou”) and that, over the centuries, “mishou” was shortened to “misho” and, eventually, “miso.”
Miso originally was a prized food available only to the nobility, who used it more often as a side dish for rice or as a medicine than as a soup base. Today miso is an essential part of the Japanese diet, but that came about only after miso became popular in soup, and after the warrior class during the Kamakura period (1185–1333) established the custom of having simple meals consisting of rice, one kind of soup and one other dish of fish or vegetables.

Over 1,300 years miso evolved a wide variety of regional variations, each made distinctive by the ingredients used, the local climate, and local diet and preferences. Even now miso types are known by the regions in which they originated: Shinshu, Kaga, Sendai, Saikyo. Miso has lost some of its local color and now comes in more shapes and sizes than ever. Today, industrially mass-produced miso from large manufacturers is sold throughout the world.