The Azumi Basin is part of the Matsumoto Basin in Nagano Prefecture, Japan. It covers approximately the municipalities of Azumino, Ikeda and Matsukawa, and some parts of Matsumoto and Ōmachi. Formerly called Azumidaira, it stretches from the west banks of the Azusa and Sai rivers to the foot of the Hida Mountains in the west, and towards the southernmost watershed of the Takase River. It is known for its natural environment, museums and art galleries.

Azumino is a city located in Nagano Prefecture, Japan. As of 1 March 2019, the city had an estimated population of 97,761 in 39744 households. and a population density of 290 persons per km2. Its total area is 331.78 square kilometres (128.10 sq mi).