The study of Armor is fascinating. Early Japanese armor was made of leather, sewn together with fibers.
A great deal of thought was put into what part of the cow or other animal was the most durable. One high ranking Japanese guy had a suit or cuirass made from cow's knees. His logic was that this was the most durable leather since the cow knelt there.
Since many Japanese were Hindu, there was a prohibition against using animal products, so a very low and shunned caste was developed called the "eta" who worked with animal products. After processing into leather, the logic was that it was ok to use it.
This same logic prevailed when eating venison, which the Japanese called "mountain whale."
The early metal plates armor was held together by fibers, until chain mail was invented. Actually early Japanese armor did not use chain mail except to hold the plates together.
Japanese armor is very ingenious. There was a type that when a bow was drawn, slid back from the drawing arm to give greater flexibility, but when the arm was lowered, slid forward to cover it.