The influence on contemporary Japanese pottery from medieval kilns is still profound and deep, even though we have one foot into the 21st century. These high-fired unglazed stonewares can be found in potting centers commonly referred to as the Six Old Kilns (rokkoyo) -- the only problem is that this term is out of date and in a sense not true. At least 77 other ancient kiln sites belonging to the Sue tradition (5th-12th centuries) have been discovered, leaving the "six old kiln" theory in the shard pile.
One great kiln not on the original six list is that of Iga. The Iga kilns, located in Mie Prefecture, are said to have been established during the Keicho Era under the guidance of the Tsutsui and later the Toda daimyo families, with the most famous kilns being the Makiyama and Marubashira.
One of the most celebrated mizusashi (water jars) in all Japan is the Iga "Yaburebukuro (Burst Bag)" which was most likely fired in one of these kilns. It has a highly distorted form with a large gash on its front; a light green glaze covers the entire body. Quite fittingly, it has been designated an Important Cultural Property.