|After the cremation in Sydney, the ashes of the submariners remained in Sydney, waiting for repatriation. For some time, they were sitting on the desk of Lieutenant John Acheson Burstal, who had been given a task of finding four large Japanese national flags to cover the caskets for the funeral the RAN held for the crew after their bodies were retrieved from the vessels.
The negotiation to exchange diplomatic personnel and civilians between Japan and the Allied countries progressed very slowly as it was a complex matter. Japanese civilians in Australia would travel to a port of a neutral country for a transfer to another boat for their journey to Japan. The same arrangement had to be made for the Allied civilians who were caught up in war in Japan and other occupied areas. Lourenšo Marques, now Maputo in Mozambique, was chosen as a suitable neutral port as it was under Portuguese control.
Shortly before departure, KAWAI Tatsuo, the Japanese diplomatic representative, was informed through the Swiss Consul-General in Sydney, H. Hedinger, that the ashes in a packet marked “J 4” were going to be sent to him. On 13 August 1942, KAWAI wrote to the Swiss Consul-General, reporting to him that the ashes were delivered to the Legation of Japan at Auburn in Victoria by the Swiss Consul in Melbourne, in person. KAWAI thanked Hedinger as well as the Australian authorities by saying that the thoughtful action by the Australian authorities would be “deeply appreciated not only by the relatives of the deceased but also ... by the whole of my fellow countrymen”. 
The exchange boat, the City of Canterbury, left Melbourne on 18 August 1942 with over 800 Japanese civilians. The submariners’ ashes were carried by KAWAI to his first-class cabin where he set up a simple altar to keep the ashes during the voyage to Africa. In order to decorate the altar, some pots of bonsai pine and oak trees and camphor branches were placed next to it. KAWAI told the submariners’ families after his arrival in Japan that he spent many hours contemplating the crew’s fate as he shared the journey across the Indian Ocean in the same cabin. He said, “These men engaged themselves in the Sydney attack even though they knew they could not return alive. I do not think I could do the same thing. What a heroic deed. I admire you as your sons or brothers were the ones who were so great.”  Incidentally, Rear Admiral Muirhead-Gould also made a similar comment about the submariners in his radio broadcast in Australia. KAWAI’s comment was widely reported throughout Japan and contributed to further heighten the reverence for the submariners.
When the City of Canterbury arrived in Lourenšo Marques, the ashes were carried out first from the ship as the passengers were transferred to a Japanese exchange boat, the Kamakura Maru. The First Class smoking lounge on the Japanese boat was designated as the sacred space where the ashes were placed. A commemorative ceremony was held during their journey back to Japan on 16 September during the voyage. The passengers were divided into seven groups and paid their respects at the altar. The boat called in Singapore before reaching Yokohama on 9 October 1942. The arrival of the ashes was publicised widely throughout Japan as the correspondents had already filed detailed reports of the Sydney attack and subsequent Navy funeral from Singapore. The entire nation was anticipating the arrival.
1. National Archives of Australia, (MP1185/8 1877/13/320). Letter from Tatsuo Kawai to H. Hedinger on 13 August 1942.
2. Osaka Mainichi Shinbun, 10 October 1942
Midget Submarine Links