“Ego” is made by boiling and dissolving seaweed called “ego-so” and hardening it, and is a local traditional dish in Niigata. At a time when refrigerators did not yet exist, it is a highly preserved marine product that has a valuable ingredient for obtaining nutrients that were often in short supply in Nagano as it has no ocean. It is said that ego-so which came from Niigata, was sold out in the Hokushin region and rarely reached the larger towns of Nagano and Matsumoto, and that it was introduced and took root mainly in the northern part of Nagano Prefecture.