Some of the kilns improved their technology and are called the "Six Old Kilns": Shigaraki (Shigaraki ware), Tamba, Bizen, Tokoname, Echizen, and Seto. Among these, the Seto kiln in Owari Province (present day Aichi Prefecture) had a glaze technique. According to legend, Katō Shirozaemon Kagemasa (also known as Tōshirō) studied ceramic techniques in China and brought high-fired glazed ceramic to Seto in 1223. The Seto kiln primarily imitated Chinese ceramics as a substitute for the Chinese product. It developed various glazes: ash brown, iron black, feldspar white, and copper green. The wares were so widely used that "Seto-mono" ("product of Seto") became the generic term for ceramics in Japan. Seto kiln also produced unglazed stoneware. In the late 16th century, many Seto potters fleeing the civil wars moved to Mino Province in the Gifu Prefecture, where they produced glazed pottery: Yellow Seto ("Ki-Seto"), Shino, Black Seto ("Seto-Guro"), and Oribe ware. According to chronicles in 1406, the Yongle Emperor (1360–1424) of the Ming dynasty bestowed ten Jian ware bowls from the Song dynasty to the "shōgun" Ashikaga Yoshimitsu (1358–1408), who ruled during the Muromachi period. A number of Japanese monks who traveled to monasteries in China also brought pieces back home. As they became valued for tea ceremonies, more pieces were imported from China where they became highly prized goods. Five of these vessels from the southern Song dynasty are so highly valued that they were included by the government in the . Jian ware was later produced and further developed as "tenmoku" and was highly priced during tea ceremonies of this time. From the middle of the 11th century to the 16th century, Japan imported much Chinese celadon greenware, white porcelain, and blue-and-white ware. Japan also imported Chinese pottery as well as Korean and Vietnamese ceramics. Such Chinese ceramics (Tenmoku) were regarded as sophisticated items, which the upper classes used in the tea ceremony. The Japanese also ordered custom-designed ceramics from Chinese kilns.