Photo/IllutrationA requisitioned vessel called Rima Maru (Provided by the War Memorial Maritime Museum)

  • Photo/Illustraion
  • Photo/Illustraion

NISHINOOMOTE, Kagoshima Prefecture--When the Rima Maru was sunk by the U.S. military in the East China Sea in February 1944, many bodies of the more than 2,700 Japanese troops are said to have washed ashore on an uninhabited island here.

As their remains are believed to have been temporarily buried on Mageshima, the health ministry has studied the 8-square-kilometer islet, 74 years after the tragedy. The effort has many former islanders and others hoping that the remains of the soldiers will be returned to their bereaved families.

The initiative is also expected to shed light on the forgotten history of thousands of requisitioned private vessels sunk during World War II such as the Rima Maru.


The Rima Maru, owned by Nippon Yusen KK, was requisitioned by the Imperial Japanese Army to transport military personnel and others.

According to a survey by the War Memorial Maritime Museum in Kobe, the Rima Maru and 3,241 military personnel left the Moji port in what is now Kita-Kyushu in Fukuoka Prefecture for Hong Kong on Feb. 7, 1944.

The following day, the vessel was sunk in waters southwest of the main island of Kyushu with torpedoes fired by a U.S. submarine.

It sank more than 300 kilometers off Mageshima, but many bodies of the dead are believed to have washed ashore onto the island 10 to 15 days later.

At the request of Nishinoomote city, the Ministry of Health, Labor and Welfare in June this year interviewed former residents of Mageshima who have knowledge of the events that transpired then. In the interviews, former islanders said remains were temporarily buried at four locations in coastal areas on the island.

The ministry also received other reports. While one states, “Identified soldiers were cremated with their name tags,” another says, “Remains of 96 soldiers were collected in 1958 for a memorial service.”

Based on such information, the ministry decided there still are remains of the troops from the Rima Maru there and excavated the burial places on a trial basis from Oct. 30 to Nov. 1.

Noboru Oshikawa, 84, a former islander interviewed by the ministry, said his father, who was a local fire brigade member, helped temporarily bury remains.

“(I heard from my father) that it was hard to deal with so many remains,” Oshikawa said. “The existence of remains has long weighed on my mind. I hope as many remains as possible will be able to be returned to their families.”

Enacted as lawmaker-initiated legislation in 2016, the war dead remains recovery promotion law specifies “retrieval of remains as the responsibility of the state” and describes the duration through fiscal 2024 as an intensive recovery period.

If remains on Mageshima are identified as those from the Rima Maru, it will be the first time in at least 10 years that remains of the war dead have been found outside Okinawa and Tokyo's Iwoto island, both of which are among the bloodiest battlefields in World War II.

According to the ministry, identified remains on Mageshima will go through DNA analysis so that they can be returned to their bereaved families.

Personal belongings and other clues to identities are often not discovered, so unidentified remains are planned to be sent to the Chidorigafuchi National Cemetery in the capital.

In a separate effort, a team of researchers conducted a survey in August to locate four wartime requisitioned vessels with an unmanned submarine in the waters where the Rima Maru sank.

Although the Taiyo Maru, a large merchant ship whose 817 civilians and military personnel were killed, was discovered during the search, the Rima Maru and two other vessels were not found at the time.

Tamaki Ura, a maritime engineering professor at the Kyushu Institute of Technology, who headed the team, said more than 7,000 private vessels victimized during the war have historically been shrouded in secrecy.

“The number of victims of the Rima Maru is higher than that of the battleship Musashi and comparable to that of the battleship Yamato,” said Ura. “But the tragic history of the requisitioned vessel has been forgotten.”


Pillboxes were set up and the Imperial Japanese Navy was stationed on Mageshima during World War II.

The island had a population of 528 in the peak period due to the immigration policy following the end of the war. However, it has been deserted since 1980, while a leisure facility and oil storage plant were planned there.

Mageshima is now deemed as a candidate site for the takeoff and landing drills of U.S. carrier-borne planes. The training is currently conducted on Iwoto.

The government has been holding discussions with Taston Airport, a Tokyo-based company that owns most of Mageshima, to buy the land, but they have yet to reach an agreement over the purchase price.

Taston Airport said it will cooperate with the ministry survey.