Indigo dyeing is a hand dyeing method that uses indigo leaves, a plant belonging to the Polygonaceae family, and has a history of more than 1,000 years, and is said to have been introduced to Japan during the Asuka period . The unique blue color created by indigo dyeing is called indigo and is a color that symbolizes Japan. It is known overseas as " Japan Blue ." Indigo dyeing comes in a variety of blues. The shade of blue changes depending on the number of times it is dyed, allowing you to express many different shades of blue.