This is often served in a soup form with most Japanese meals.
Miso is a traditional Japanese seasoning that we cannot live without. It is said to have been derived from the ancient Chinese paste, hishio. Hishio is made by mixing ground meat and fish with salt and alcohol and marinating it in a container for at least 100 days to age. It is believed that, in the 1st century B.C., a paste called shi, which was created from fermenting soybeans and millet, had made its way from China and the Korean peninsula to Japan. Japan might have used this paste as a prototype to evolve its own paste; this is the miso we know today.
“Honda Miso Honten was founded about 190 years ago in the Tempo era of the Edo period. It all began when Tanbaya, our first-generation master brewer, was recognized for his expert skill in rice malt-making and presented his miso to the Imperial Palace to use in their dishes. Since then, we have supplied our miso to the Imperial Palace, but our products became available to the general public with the start of the Meiji Restoration. During that time, Edo became known as “Tokyo” (Eastern Capital), and Kyoto was called “Saikyo” (Western Capital). As a result, our miso became known as “Saikyo Miso” and is now adored by many.”
See their beautiful website: http://www.honda-miso.co.jp/en/