Warazan (藁算) was a system of record-keeping using knotted straw at the time of the Ryūkyū Kingdom. In the dialect of the Sakishima Islands it was known as barasan and on Okinawa Island as warazani or warazai. Formerly used in particular in relation to the "head tax", it is still to be found in connection with the annual Itoman Giant Tug-of-War (糸満大綱引), to record the amount of miki or sacred sake dedicated. (Wikipedia).