Edamame bean is a preparation of immature soybeans in the pod, found in the cuisine of China, Japan and Hawaii. It have been a staple of the Asian diet for 5,000 years. An important source of plant protein. The earliest documented reference to the term edamame dates from the year 1275, when the well-known Japanese monk, Nichiren, wrote a note thanking a parishioner for the gift of edamame he had left at the temple. Soybeans were first introduced to Europe in the early 1700s and to the British colonies in 1765 where it was first grown for hay. Benjamin Franklin wrote a letter in 1770 mentioning sending soybeans from from England. Delicious edamame recipes.