, or sometimes just , is an inhabited island located roughly 1.5 kilometers northeast of the city of Niihama (which it is officially a part of) in

Ehime Prefecture is a prefecture of Japan located on the island of Shikoku. Ehime Prefecture has a population of 1,342,011 (1 June 2019) and has a geographic area of 5,676 km2 (2,191 sq mi). Ehime Prefecture borders Kagawa Prefecture to the northeast, Toku ...

Japan Japan ( ja, 日本, or , and formally , ''Nihonkoku'') is an island country in East Asia. It is situated in the northwest Pacific Ocean, and is bordered on the west by the Sea of Japan, while extending from the Sea of Okhotsk in the north ...

Geography

Nii Ōshima is located in the

Seto Inland Sea The , sometimes shortened to the Inland Sea, is the body of water separating Honshū, Shikoku, and Kyūshū, three of the four main islands of Japan. It serves as a waterway connecting the Pacific Ocean to the Sea of Japan. It connects to Osaka ...

. It has a circumference of approximately 8 kilometers and a total area of . The island is mostly hilly, with its highest point at 146.48 meters above sea level. The northern part of the island is covered with dense forests, has many cliffs. The main settlement is in the southern part of the island. There is a ferry that runs between Nii Ōshima and Niihama approximately once every hour, taking fifteen minutes to complete a one-way journey. At one point there was the possibility that a bridge might be built to connect Ōshima and Shikoku, but these plans are now considered unlikely. There is no public transportation on the island, but there is a road that circles the island.

History

Nii Ōshima was the birthplace of Murakami Yoshihiro (d.1374), founder of the "Murakami Navy", who ruled the Seto Inland Sea in the

Muromachi The is a division of Japanese history running from approximately 1336 to 1573. The period marks the governance of the Muromachi or Ashikaga shogunate (''Muromachi bakufu'' or ''Ashikaga bakufu''), which was officially established in 1338 by t ...

and

Sengoku period The was a period in History of Japan, Japanese history of near-constant civil war and social upheaval from 1467 to 1615. The Sengoku period was initiated by the Ōnin War in 1467 which collapsed the Feudalism, feudal system of Japan under the ...

. On the southern side of the island sit the remains of Ōshima Castle, which was one of the Murakami strongholds. The island became Ōshima Village in Ehime Prefecture, with the establishment of the modern municipalities system on December 15, 1889. The village was absorbed by Niihama City on May 3, 1953. Due to its rapidly aging population and its geographic isolation from Niihama and the main island of

Shikoku is the smallest of the four main islands of Japan. It is long and between wide. It has a population of 3.8 million (, 3.1%). It is south of Honshu and northeast of Kyushu. Shikoku's ancient names include ''Iyo-no-futana-shima'' (), '' ...

, Nii Ōshima faces serious problems of

rural depopulation Rural flight (or rural exodus) is the migratory pattern of peoples from rural areas into urban areas. It is urbanization seen from the rural perspective. In industrializing economies like Britain in the eighteenth century or East Asia in the ...

. At the time of 1950 census, the population of the island was 1838 people. However, per Niihama City residency records, the population as of March 31, 2013, was only 280, with half the population over the age of 70. The primary occupations on the island include

shrimp farming Shrimp farming is an aquaculture business that exists in either a marine or freshwater environment, producing shrimp or prawns (crustaceans of the groups Caridea or Dendrobranchiata) for human consumption. Marine Commercial marine shrimp farming ...

and agriculture, particularly

mikan ''Citrus unshiu'' is a semi-seedless and easy-peeling citrus species, also known as miyagawa mandarin, unshu mikan, cold hardy mandarin, satsuma mandarin, satsuma orange, naartjie, and tangerine. ''Citrus unshiu'' was named after Unshu (Wenzho ...

and a distinctive type of white

potato The potato is a starchy food, a tuber of the plant ''Solanum tuberosum'' and is a root vegetable native to the Americas. The plant is a perennial in the nightshade family Solanaceae. Wild potato species can be found from the southern Unit ...

. Islands of Ehime Prefecture Dissolved municipalities of Ehime Prefecture Niihama, Ehime {{Ehime-geo-stub