From Chris Dickerson citing journals of Capt Todd:

The first occupants of Rokuroshi were 30 men from the prison camps at Tsmori and Umeda in the Osaka district. They camp to this camp on or about the 18th of May. In the group that came here there were 5 English, 5 Dutch, 11 civilians from Wake Island, 7 Marines and 2 Navy men. They are as follows:

According to Todd's journals, the following were at Rokuroshi as of on or about May 18, 1945:

American Marines (Wake): James O. Boscarino; Franklin Gross, Frank J. Novak, Edward W. French, E. O. S. Adams; Neil O. Rider, A Harting

American Navy (Wake): Edwin Bahr, R. S. Butler

Civilians from Wake: D. L. Brauer, M. M. Donoho, E. G. Mitchell, R. D. Perrine, Jo. An. Anderson, C. H. Bray, H. W. Cerny, T. T. Cope, J. W. Cape, W. J. DeLop, J. A. Nelson

English (Sing.): J. A. William, Cyril Rhodes, J. J. Robinson, H. H. Skeet, Arthur Thomas

Dutch: T. W. Van Loo, A. E. Van Lommel, Th. W. F. Van Doomberg, G. W. Van Kuyk, J. G. F. De Crooy