Former head offices of Kosaka mine
Former head offices of Kosaka mine
Flag of Kosaka
Official seal of Kosaka
Location of Kosaka in Akita Prefecture
Location of Kosaka in Akita Prefecture
Kosaka is located in Japan
Coordinates: 40°19′59″N 140°44′10″E / 40.33306°N 140.73611°E / 40.33306; 140.73611Coordinates: 40°19′59″N 140°44′10″E / 40.33306°N 140.73611°E / 40.33306; 140.73611
 • Total201.70 km2 (77.88 sq mi)
 (July 1, 2021)
 • Total4,646
 • Density23/km2 (60/sq mi)
Time zoneUTC+9 (Japan Standard Time)
- TreePrunus sargentii
- FlowerAcacia
-FishSockeye salmon
Phone number0186-29-3901
AddressOtarube 37-2, Kosaka-kozan, Kosakamachi, Kazuno-gun, Akita-ken 017-0292
WebsiteOfficial website
Kosaka Town Hall (originally a middle school)
Kosaka Town Hall (originally a middle school)

Kosaka (小坂町, Kosaka-machi) is a town located in Akita Prefecture, Japan. As of 1 July 2021, the town had an estimated population of 4,646 in 2,368 households, and a population density 23 persons per km².[1] 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.[2]


Kosaka is located in the Ōu Mountains the mountains of far northeastern Akita Prefecture, with Aomori Prefecture on the north, and Lake Towada to the northeast. Much of the town is within the borders of the Towada-Hachimantai National Park. Much of the town area is covered in forest. Due to its inland location, the town is noted for its heavy snowfall in winter.

Neighboring municipalities


Per Japanese census data,[3] the population of Kosaka has declined over the past 40 years, and is less than half of what it once was in 1970.

Historical population
1960 15,676—    
1970 13,768−12.2%
1980 10,526−23.5%
1990 8,035−23.7%
2000 7,171−10.8%
2010 6,054−15.6%


Kosaka has a cold Humid continental climate characterized by cool short summers and long cold winters with heavy snowfall and (Köppen climate classification Dfa). The average annual temperature in Kosaka is 8.4 °C. The average annual rainfall is 1466 mm with September as the wettest month. The temperatures are highest on average in August, at around 22.2 °C, and lowest in January, at around -4.3 °C.[4]


The area of present-day Kosaka was part of ancient Mutsu Province and was ruled by the Nambu clan of Morioka Domain during the Edo period. The “Kosaka-kaido” highway connecting Morioka Domain with Hirosaki Domain passed through Kosaka. Under the Nambu, major deposits of gold and silver were mined by the Fujita-gumi, the predecessor to modern Dowa Holdings for the Nambu clan at the Kosaka mine. After the start of the Meiji period, the area became briefly part of Rikuchū Province before being transferred to Akita Prefecture in 1871. It was organized as part of Kazuno District, Akita Prefecture in 1878. The village of Kosaka was created with the establishment of the modern municipalities system on April 1, 1889. It was raised to town status on May 12, 1914.


With the depletion of the mineral deposits at the Kosaka Mine from the 1990s, the economy of Kosaka is now largely based on agriculture, forestry and seasonal tourism. Dowa Holdings, the owner of the Kosaka Mine is active in the metal recycling industry. In terms of light manufacturing, the Towada Audio Corporation, a manufacturer of shortwave radio sets, TV tuners and AC adapters in the Sony group, is based in Kosaka.


Kosaka has one public elementary school and one public middle school operated by the town government and one public high school operated by the Akita Prefectural Board of Education.



The Kosaka Smelting & Refining Kosaka Line provided passenger services until 1994. At present, the town is not served by any passenger railway line.


Local attractions

Korakukan Kabuki theatre
Korakukan Kabuki theatre
Kosaka Railroad Rail Park
Kosaka Railroad Rail Park