Iga Yaki is pottery made primarily in Iga City, Mie Prefecture. Production began in the Kamakura period (1185 to 1333). The fire-resistant clay, sourced from an ancient bed of Lake Biwa originally located in the Iga City area, contains lignite. This contributes to Iga Yaki's distinct firing properties and unique characteristics. These include "bidoro" (a natural glaze resulting from scorching) and "yohen" (changes not intentionally applied by the potter, but occurring in the kiln). In addition, the clay supports powerful forms, allowing for bold, natural shaping. The demanding “Iga's Nanadoyaki,” or Seven Firings of Iga, involves multiple high-temperature firings that often result in breakage, meaning only a small number of pieces are retrieved as finished products.