Maruo Yaki, a unique ceramic from Kumamoto Prefecture's Amakusa region and part of Amakusa Tōjiki, was established in 1865 by the Kanazawa family. Early production focused on "coarse wares" such as jars and pipes. Sourced from local red clay and Amakusa Tōseki porcelain stone, Maruo Yaki uses specific glaze formulas (milky white, black, green, transparent), perfected by its 3rd generation. A hallmark is the yohen nagashi-yu (kiln-change poured glaze) that transforms unpredictably during firing, creating a warm, rustic charm. This glaze enhances each piece's simple beauty and ensures no two are alike. Today, Maruo Yaki continues to produce ceramics rooted in local materials and methods, designated a National Traditional Craft in 2003.