A whopping four hours on the shinkansen from Tokyo Station to Akita and another hour on the local train to the city of Oga, located on a small peninsula jutting out from northwestern Akita Prefecture, brings us to Moroi Jozo, the soy sauce maker who single-handedly revived shottsuru production.
Shottsuru is a fish sauce made in Akita Prefecture from sandfish (hatahata). Though fish sauce was historically made in numerous locales along the almost 30,000-kilometer-long Japanese coastline, nowadays the region is one of just two major producing areas, the other being Ishikawa Prefecture, where the sauce is called ishiri or ishiru.
Other minor producing regions exist: The Seto Inland Sea area has maintained a minute production of sand lance fish sauce (ikanago shoyu) and Hokkaido is developing salmon fish sauce due to its extensive salmon catch, but fish sauce has historically been a hyperlocal ingredient in Japan.