U.S. Marine Allen Nelson first visited Okinawa in 1966 when the entire island was under American control and functioned as its springboard for the war in Vietnam. For two weeks, Nelson and his fellow new recruits spent their days practising guerilla warfare at Camp Hansen, central Okinawa, then in the nights, they headed into civilian areas to drink, fight and look for women. In later interviews, Nelson recalled drunken U.S. Marines beating taxi drivers and bar workers unconscious: "When we are coming to town, we don't leave our violence on military bases. We bring our violence into towns with us."

The next time Nelson visited Okinawa was 30 years later. This time when he visited local communities, he brought something very different: the message that the U.S. military presence on the island was unjust and the bases should be closed immediately.

What had happened in those intervening years to transform Nelson's stance so profoundly has been explored in numerous Japanese books, TV shows and even a manga published in 2005 titled "Nelson-san, Anata wa Hito o Koroshimashitaka" ("Mr. Nelson, Did You Kill People?"). But very little has been written in English about the former marine and, although his story cuts to the core of current U.S.-Japan relations, he remains largely unknown in his home country.