Intact military remains found on island in southern Japan

August 8, 2022

TOKYO – A local school board in Kagoshima Prefecture has discovered intact remains of Imperial Japanese military installations on Kakeroma Island, which is part of the Amami Islands in the prefecture.

The Municipality of Setouchi is seeking national historic site status for six sites, including a cannon battery and a base that has launched suicide bombings in motorboats. If successful, it will be the first time that military installations built during the Taisho and Showa eras (1912-1926 and 1926-1989, respectively) will receive this designation.

Due to its location between the Kyushu region and Okinawa Prefecture, Amami-Oshima Island, the main island of the Amami Island chain, was considered a strategic location for national defense. In 1891, the former Imperial Japanese Navy established supply facilities on the island, while the former Imperial Japanese Army established a fortress command post there in the late Taisho era. During the Pacific War, the Navy deployed the Oshima Defense Unit and a Shinyo Suicide Boat Base to Kakeroma Island, which lies across from Amami-Oshima Island. Toshio Shimao (1917-1986), who became a well-known novelist after the war, led the 18th Shinyo Unit.

A compartment for a Shinyo suicide boat carved into a mountain near a creek is seen in Setouchi, Kagoshima Prefecture.
Pictures of Yomiuri Shimbun

After the war, the Municipality of Setouchi maintained some facilities, but a survey of facilities in the mountains and remote creeks of the settlements found several intact remains. The city’s board of education surveyed and searched all six sites in the 2017-2021 exercise, including Nishikomi Battery, Ankyaba Battery and the 18th Shinyo Suicide Boat Attack Base.

As a result, the remains of more than 80 military installations were found, including gun emplacement, ammunition depots, observation posts, barracks and piers. At Nishikomi Battery in the western part of Amami-Oshima, four concrete gun emplacements and two ammunition storage buildings were discovered in a subtropical forest.

The remains of a Nishikomi battery ammunition storage facility in Setouchi, Kagoshima Prefecture.
Pictures of Yomiuri Shimbun

The remains of Tokyo Bay Fortress in Yokosuka, Kanagawa Prefecture, built during the Meiji era (1868-1912), have been designated a National Historic Site. Five of Setouchi’s six military remains were built later.

The Setouchi School Board believes the remains are valuable as they provide clues to the operation and transition of military installations towards the end of World War II. The council intends to submit an application to the Cultural Affairs Agency for a national historic site designation by the end of this fiscal year.

“Unlike the facilities on Okinawa Island and the Japanese Archipelago, these remains are remarkable in that they were not destroyed in battle or by development projects,” said Yoshihiko Akashi, director of the Onojo Cocoro-no-furusato-kan city museum and chairman of the city’s modern remains survey committee. “It’s also significant as the remains show the full extent of the base, which served as the front line for the main defense during the later stages of World War II.”