What is "do-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 O-yoroi style it became more common in the Genpei War at the end of the 12th century.