The bodies of the crew of the I-124 submarine remain where the vessel was sunk by the allies.
It is largely unknown how many Japanese died during the attacks in northern Australia, but two descendants of one of the crewmen travelled from Japan for a special ceremony which aimed to bridge some of the divide between once bitter enemies.
The plaque was laid at the cliffs overlooking Casuarina Beach, near the water where the wreck of the submarine is concealed.
One of the men who died was Petty Officer Second Class Ryohei Ootak. His grandson, Takashi Otaki, and great-nephew, Shichiro Chiba, travelled to Darwin for the first time to see the place where their ancestor rests.
“I am deeply moved that Australia has chosen to honour the enemy loss as well as their own,” he said.
Both men said they grew up knowing of their relative’s war efforts, but seeing the site where his body rests will be very significant.
The I-124 was one of four mine-laying submarines sent to north Australian waters on secret missions to intercept allied vessels during World War II.
In what would be the submarine’s final mission, the crew were trying to torpedo an oil tanker when it was hit by another vessel which had come in to defend the tanker.
The submarine sank, killing all crew.
Controversy has plagued the I-124 over the past 70 years.
Strange stories and theories surround the wreck, including that valuable mercury was on board.
There were also rumours that Japanese codebooks were recovered from the wreck, helping to win the Pacific war, although that claim was later disproven by Australian historian Dr Tom Lewis. - ABC