This original "kokiran" military shirt is made of a high-gauge cotton ripstop fabric using yarns dyed with synthetic and natural indigo. "Kokiran" is a very deep blue and is a color loved by the common people since the Heian period (794 - 1180). At that time, the color was actually a combination of indigo and yellow known as "kihada", and we've reproduced this color here through a special process that utilizes modern dyes.