The Oitomi iron foundry is located in the Mizusawa district, which is known for its long tradition of creating Nambu ironware.

Nambu ironware has its roots in mid-17th century Japan, where the Nambu clan invited skilled foundry craftsmen from Kyoto to produce Buddhist altars and tea kettles in Mizusawa, as it was easy to obtain minerals and iron sand as raw material, and charcoal as fuel.

The Oitomi iron foundry was established in 1848 by a collective of skilled craftsmen with a focus on the art of creating traditional Nambu ironware. With a history spanning 170 years, the Oitomi foundry has contributed to protecting and passing on the unique skills and customs associated with the craft.

Oitomi specializes in the manufacture of traditional Japanese cast iron teapots, but also makes a few other products.