Ooboriso Oma Yaki has been around for more than three hundred years and it continues to be a staple of Fukushima. When Ooboriso Oma Yaki is taken out of the kiln after baking, it makes a crisp ringing sound, the pottery then expands and forms cracks on the surface. Bringing back Ooboriso Oma Yaki is a sign that Fukushima is reviving, slowly, but surely. Every Ooborisa Oma Yaki teacup has a double-layered structure called: Nijyuu-Yaki. The inner layer of the cup holds the hot tea and the outer layer blocks the heat which allows people to hold onto the cup comfortably without feeling the heat.