Sano City has been known as Tenmyo since ancient times, and it is believed that casting in Sano began in mid-Heian period (901 to 1068) when Hijiwara-no Hidesato, Lord of Karasawa Castle in Sano invited metal casting experts from Kawachi to come and begin making products ranging from kettles to weaponry to Buddhist altar vases. Thus began the Tenmyo-imono craft tradition. The craft reached its peak from the Muromachi period to the early Edo period. What makes these products especially treasured are how they balance elegance of form with rustic surface textures. In particular, Sano City is proud of its Tenmyo-imono tea kettles, which were beloved by Sen Rikyu, founder of the tea ceremony.