From Halopedia, the Halo wiki
The physical architecture of the Yoroi armor draws inspiration from its namesake, a Japanese armor named ō-yoroi, including characteristics like a large crest on the helmet, a neck guard made of curved plates, horizontal rows of armor plates on the arm shoulders, and the uwa-obi around the waist. The armor below the waist resembled the haidate, which were thigh guards that tied around the waist and covered the thighs. A small blade is also secured on the waist, with the handle on the wearer's right-hand side for use when grappling in close quarters.
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