This is a Bizen Ware teacup with a pattern called sangiri. The coarse texture, exquisite colors, and patterns produced by the kiln's flames are a remarkable example of Bizen Ware, "the art of clay and fire."

The "san" in sangiri refers to the wall inside the kiln. The work placed on the side of the wall where ash tends to accumulate is covered with ash from pine wood, and the parts of the work not directly exposed to the fire react with the ash, turning them grayish brown or blackish brown. Each firing results in a different pattern, making each piece a unique work of art.