To the east of Iwate lies the Kitakami plateau, limestone and granite. To the west stands the Ou range, volcanic rock and tuff, with Mount Iwate rising past two thousand metres. Between those two geologies, clear groundwater and spring water come up all over the prefecture, and that is the first thing anybody says about sake made here.

The second thing is the people. The Nanbu toji are a guild of brewmasters based in this province, said to be the largest such group in the country. They did not only brew at home. They travelled out to breweries in other regions for the winter season and came back in spring, which is why the name is known far outside Iwate.

The sake is soft in the mouth, with the savouriness of the rice brought forward rather than held back. People describe the aroma as green bamboo, or new leaves. In the junmai ginjo grades it moves towards green apple and pear.

In September 2023 the name of the prefecture was registered with the tax agency as a protected origin for sake. The water has been here since the mountains were made and the brewers for several centuries. Of the three things this sake rests on, the name is by a very long way the newest.