Today the word "soba" means buckwheat, in particular buckwheat noodles, in Japanese. This word is in origin an abbreviation of "soba-mugi" (buckwheat). The word "soba" refers to the edge in ancient Japanese and "soba-mugi" meant "edgy wheat". Around the 16th century, buckwheat began to be processed into thin noodles. This method was originally known as "soba-kiri" (lit. soba cutting) but it was later abbreviated into "soba". Soba was mainly consumed in eastern Japan and was not popular in western Japan or on Okinawa. Buckwheat noodles remain rare on Okinawa, where they are known as "Nihon soba" (Japanese soba) or "kuroi soba" (black soba).