Kosaka (小坂町, Kosaka-machi) is a town located in Kazuno District, Akita Prefecture, Japan. As of 1 March 2023, the town had an estimated population of 4,670 in 2,284 households, and population density of 23 persons per km. The total area of the town is 201.70 square kilometres (77.88 sq mi). In 2016, Kosaka was selected as one of The Most Beautiful Villages in Japan.
Mutsu Province (陸奥国, Mutsu no Kuni; Japanese pronunciation: [mɯꜜ.tsɯ (no kɯ.ɲi)]) was an old province of Japan in the area of Fukushima, Miyagi, Iwate and Aomori Prefectures and the municipalities of Kazuno and Kosaka in Akita Prefecture.
Mutsu Province is also known as Ōshū (奥州) or Michinoku (陸奥 or 道奥). The term Ōu (奥羽) is often used to refer to the combined area of Mutsu and the neighboring province Dewa, which together make up the entire Tōhoku region.
Dewa Province (出羽国, Dewa no Kuni; Japanese pronunciation: [deꜜ.wa (no kɯ.ɲi)]) was a province of Japan comprising modern-day Yamagata Prefecture and Akita Prefecture, except for the city of Kazuno and the town of Kosaka. Dewa bordered on Mutsu and Echigō Provinces. Its abbreviated form name was Ushū (羽州).