In June 1945, following the Allied victory at the Battle of Okinawa, U.S. forces occupied the Okinawa Islands. Shortly afterward, three U.S. Marines described by villagers as "Black Americans," including one "as large as a Sumo wrestler," entered the village of Katsuyama, northwest of Nago, and raped a girl. According to villagers, the Marines returned nearly every Saturday afterward, forcing male residents to lead them to women who were then taken into the hills and raped, sometimes arriving unarmed because they believed the villagers would not resist.
In July 1945, a group of male refugees sheltering in the village, together with village men and two armed Imperial Japanese Army soldiers hiding nearby, planned an ambush. According to elderly Katsuyama residents interviewed later by The New York Times, the three Marines were shot in a narrow mountain pass and then beaten to death by several dozen villagers using sticks and stones. A resident who was a teenager at the time recalled hearing gunshots and commotion but not witnessing the killing directly. Afterward, villagers dragged the bodies up a steep slope and concealed them in a cave with a steep drop-off near its entrance, which was then sealed with rocks. The cave reportedly became known locally by a name later translated in English-language sources as "Cave of the Negroes" or "black men's cave," using a Japanese term now considered a derogatory slur for Black people.
The Marines were reported missing on 14 July 1945 and initially listed as possible deserters, before a subsequent investigation classified them as missing in action and, by mid-1946, presumed dead; they were posthumously awarded Purple Hearts. Knowledge of the killings remained a closely held village secret for approximately fifty years, spanning U.S. military governance of Okinawa and its later return to Japanese administration, though a 1978 local historical society record obliquely described the killings as "tragic."
In 1997, a Katsuyama resident, motivated by guilt after hearing accounts from village elders, contacted a tour guide involved in searching for the remains of deceased U.S. servicemen. The two searched for and located the sealed cave, and local police were informed in September 1997, though the discovery was publicly presented as an independent find by the tour guide in February 1998 to protect the resident's anonymity. The remains were transferred to U.S. military custody in April 1998 and identified in April 1999 through dental records and dog tags as Private First Class John M. Smith, Private Isaac Stokes, and Private First Class James D. Robinson, all of the segregated 37th Marine Depot Company.
Wider public attention followed an April 2000 Yomiuri Shimbun report linking Katsuyama residents to the deaths. Families of the Marines disputed that their relatives had committed rape, and The New York Times noted it was never definitively proven that the men killed were the same Marines responsible for the assaults. A Naval Criminal Investigative Service probe was announced but Okinawa prefectural police stated no prosecution was possible, as the 15-year statute of limitations had expired in 1960. The case reignited discussion of underreported wartime sexual violence by American servicemen in Okinawa.