Oshima, also known as Hyuga Oshima, is a beautiful island floating in the Hyuga-nada Sea off the coast of Miyazaki Prefecture. It belongs to Nakamuraotsu in Nango Town, Nichinan City, and is known for its natural surroundings and secluded island atmosphere.
Under the Miyazaki Prefecture Remote Islands Promotion Plan, established in accordance with Japan’s Remote Islands Development Act, Oshima is designated as part of the Minami-Naka Islands, together with Tsukishima Island in Kushima City. This designation recognizes the island as an area requiring support for the improvement of living conditions and infrastructure.
Oshima lies approximately 7 kilometers southeast of central Nichinan City and about 2.5 kilometers east of the mainland coast at Nango Town. It is a mainland-adjacent island facing the open sea.
Fishing has traditionally been the island’s principal industry. Under the Remote Islands Development Act, improvements have been made to essential infrastructure, including port facilities, a simplified water supply system, and electricity services.
At its peak, more than 300 people lived on Oshima. The island once supported a small but active community whose livelihood was closely connected with the surrounding sea.
In 2015, the last resident left Oshima, and the island temporarily became uninhabited.
Following this, former island residents and other people connected with Oshima established the Oshima Project Conference. The group began working to revitalize the island through activities such as guided walking tours, the development of walking trails, and fruit cultivation.
These initiatives were intended to make use of the island’s natural environment while creating new reasons for people to visit and rediscover its appeal.
In 2020, the island hosted an art project called Nango Oshima Museum. Through artworks and creative activities, the project introduced Oshima’s landscape and unique character to a wider audience.
Rather than relying solely on conventional sightseeing facilities, the project used art to bring attention to the island’s natural environment and its potential as a place for cultural experiences.
According to the figures dated April 1, 2022, Oshima had two residents.
Although the population is very small compared with the island’s former community of more than 300 people, the return of residents means that Oshima is once again an inhabited island.
The community-led projects, walking tours, and other revitalization efforts have helped maintain interest in the island and its future.
One of the facilities on Oshima is Adventure Cabin, a municipal accommodation facility created by renovating the former Oshima Elementary School building.
The elementary school closed in 1980, and its former school building was subsequently adapted for use as accommodation. It now provides a place where visitors can stay while exploring the island.
Repurposing the former school has given the building a new role and allows it to continue serving the island community and its visitors.
Another important landmark on Oshima is Kuranosaki Lighthouse. First lit in 1884, it is notable as Japan’s first building constructed using unreinforced concrete.
The lighthouse has watched over the surrounding sea for more than 120 years. Its historical construction method makes it an important example of early lighthouse engineering in Japan.
In addition to its practical role in maritime navigation, Kuranosaki Lighthouse is a valuable historical structure that reflects the development of coastal infrastructure during the Meiji period (1868–1912).
The only public transportation service connecting Oshima with the mainland is a municipal passenger boat operating between Meitsu Port in Nango Town, Nichinan City, and the island.
The passenger boat service was established in 1990. The crossing takes approximately 15 minutes, and the boat operates four round trips per day.
After departing from Meitsu Port, the boat first stops at Takenojiri Port, located in the southwestern part of Oshima. It then continues to Kohama Port in the northwestern part of the island.
Kohama Port is the island’s main harbor and serves as an important transportation point for both local residents and visitors.
Because the passenger boat is the island’s only public transportation connection with the mainland, visitors should check the operating schedule in advance and plan their visit around the departure and return times.
Oshima is surrounded by the Hyuga-nada Sea, a large marine area off the eastern coast of Miyazaki Prefecture. Hyuga-nada forms part of the Philippine Sea and is also part of the wider Pacific Ocean.
The name generally refers to the stretch of sea extending from Cape Toi, at the southern end of Miyazaki Prefecture, northward to Cape Tsurumisaki in Saiki City, Oita Prefecture.
The warm Kuroshio Current flows into Hyuga-nada, bringing favorable conditions for a wide variety of marine life.
Fish such as sardines, tuna, and bonito migrate through these waters, making the area an important fishing ground.
The surrounding coastline is also known for its beautiful scenery. Protected coastal areas include the Nippō Coast Quasi-National Park and the Nichinan Coast Quasi-National Park, both of which feature attractive coastal landscapes.
The area also contains tourism facilities such as Seagaia, adding to the region’s appeal as a destination where visitors can enjoy both the sea and leisure activities.
The coastal region around Hyuga-nada was once known as a production area for Go stones, the playing pieces used in the traditional Japanese board game Go.
Clams were used as the raw material for these stones. However, the clam population was driven close to extinction, and the industry subsequently declined.
This history illustrates how the region’s traditional industries were closely connected to the natural resources of the sea.
Hyuga-nada once supported a rich marine ecosystem that included various species of whales, such as the blue whale, as well as Japanese sea lions.
Although these animals are no longer a familiar part of the area’s coastal environment, their historical presence reflects the diversity of marine life that once inhabited the waters.
The name Iruka Cape (Dolphin Cape), which remains in use in Nichinan City, is another reminder of the area’s close relationship with marine wildlife.
Hyuga-nada is located within the broader Nankai Trough region, where large earthquakes have occurred repeatedly throughout history.
The area is also considered in assessments of the potential impacts of a future major Nankai Trough earthquake. The source article notes the possibility of tsunami waves reaching a maximum height of 12 meters in parts of the Hyuga-nada area.
Because the coastline is exposed to earthquake and tsunami hazards, preparedness is essential for coastal communities. Visitors should also be aware of local evacuation information and follow official instructions in the event of an earthquake or tsunami warning.
Several major rivers flow from the mountains and plains of Miyazaki Prefecture into Hyuga-nada. These include:
Gokase River, Mimi River, Omaru River, Hitotsuse River, Oyodo River, and Hirowatari River.
These rivers carry water and nutrients from inland areas to the coast, supporting the region’s natural environment. They also play important roles in local industries, particularly fishing and agriculture.
Oshima offers a glimpse of a quieter side of Miyazaki Prefecture. Its location just off the coast of Nichinan, its history as a fishing community, and its efforts to revive island life make it an interesting destination for travelers seeking places beyond the main tourist routes.
Visitors can discover the island’s natural surroundings, stay in the former elementary school accommodation, and learn about the history of Kuranosaki Lighthouse. The community’s walking trails and art initiatives also offer different ways to experience the island.
The surrounding Hyuga-nada Sea adds another dimension to the visit, with its rich fishing grounds, coastal scenery, and historical connections to local industries and marine wildlife.
Oshima is a small island, but its story brings together nature, maritime culture, community history, and the ongoing efforts to preserve the character of a remote coastal settlement.