Dō-maru
Dō-maru (胴丸), or "body wrap", was a type of chest armour ("dou or dō") worn by the samurai class of feudal Japan. "Dō-maru" first started to appear in the 11th century as an armour for lesser samurai and retainers. Like the "ō-yoroi" style it became more common in the Genpei War at the end of the 12th century. Description. There were quite a number of similar styles and types of Japanese armor; the "dō-maru" is particularly defined by the fact that a "dō-maru" opens on the right side as opposed to the "haramaki  style which opened in the back and the ō-yoroi" the cuirass of which is completely open on the right side requiring a separate plate ("waidate") to cover the right side. The "ō-yoroi" was a heavy box like armour meant for use on horseback, and was expensive to make. The "dō-maru", like the "haramaki" had more skirt plates ("kusazuri") than an ō-yoroi and was lighter, closer-fitting, and cheaper to create. The "dō-maru" was easier to fight with on foot and eventually even higher status samurai adopted it over the "ō-yoroi". "Dō-maru" were constructed  from small scales of leather or metal laced into plates with cord and lacquered. Then each plate was laced together to form the armor. Due to the weight of iron, armour makers limited its use to the most vital parts of the armor and used leather for the remainder.