I was answering a question on the SCA Japan FB page and thought I’d record my answer here as well, since I just spent about an hour translating Japanese webpages.
(I found this image on a Google Search. It is from a Japanese photo blog, looks like someone taking pictures at the 2014 Jidai Matsuri parade. The photographer’s handle is EGACITE and his blog is here.)
According to the Costume Museum’s Japanese website, that particular headgear is called katsura tsutsumi 桂包 (かつらづつみ). Katsura is a village, tsutsumi is a long wrapped cloth. According to legend, the women of Katsura began wrapping their heads this way back when the Empress Jingu conquered the three Han states in Korea–the original wrapping was her belt (literally 腹帯 (ふくたい) fukutai = abdominal band, bellybelt, maternity belt, per WWWJDICT translation). It goes on to say that there is no evidence that the legend is true. Here’s a link to a different translation of the page. And yes, as Mistress Saionji says, it’s a long wrapped rectangular cloth. (Side note: Zukin are a different type of headdress–it literally translates to “hood” and was mostly seen on women who had taken Buddhist religious vows of some type.)
Here is a translation I did off of another Japanese page that was defining the term katsura tsutsumi from the Daijirin 3rd Edition: Wrap the head from behind with a long cloth such as a towel, Knot in front, then pull back the remainder on both sides of the face. This was customarily worn by common women of the Muromachi period. “Katsura” [which can mean wig] comes from the village of Katsura.
And a partial rough translation from the Encyclopedia Nipponica: A woman’s headdress from the late middle ages. Wrap the head like a headband in a long white cloth, tied a bit lower in the front. It is also called “Katsura-maki”. From Katsura Village in the Kyoto Western Suburbs. The custom was supposedly begun by fishwives and candy sellers carrying their wares. Legend claims it was bestowed on the women of Katsura by the Empress Jingu, who conquered the Three Han States (in Korea). Pictorial evidence shows this a custom of common women rather than those of the aristocracy, and there are many depictions of common women so attired.
There’s more, but I have to get back to real life. Didn’t realize there would be so much out there on a simple search. Here’s the webpage where I found the above two definitions.