Board Thread:Speculation House/@comment-14138255-20141031002615/@comment-10390252-20141111135520

LilithArcher wrote: Actually the cloth under her mask sort of looks like the type of Cloth that kendo users have under their mask: http://www.boston-kendo.com/images/guide/men-on-3.jpg

For the link I just did a quick google search. IMO, Raven's entire fighting costume looks like it's inspired by traditional kendo practice armour.