Uchidasarayama Yaki, from Amakusa, Kumamoto, is Japan's second oldest porcelain kiln site after Arita. Active for about 100 years in the mid-Edo period (c. 1700s), it was re-established in the late 20th century. Today, it reproduces folk craft white porcelain inspired by historical shards, emphasizing simple beauty. Potters use high-quality Amakusa Tōseki porcelain stone and local Shiki clay. A unique hallmark is the use of Isu ash (isu-bai) from specially cultivated Isu trees, which acts as a flux in glazes, contributing a subtle, distinctive character and hue to the pure white surface of their wares, preserving this valuable local heritage.