data seto japanSeto, city, Aichi ken (prefecture), central Honshu, Japan, northeast of Nagoya. Seto, established about 1230, is known for its porcelain (Seto ware). Since the Meiji period (1868–1912),Seto in Northern Aichi prefecture is synonymous with ceramics in Japan. This city is home to several ceramic artists and companies. Mapcarta, the open map.