At the age of eighteen, Chad Rowan left his home in rural Hawai'i for Tokyo with visions of becoming a star athlete in Japan's national sport, sumo. But upon his arrival he was shocked less by the city crowds and the winter cold than by having to scrub toilets and answer to fifteen-year-olds who had preceded him at the sumo beya. Rowan spoke no Japanese. Of Japanese culture, he knew only what little his father, a former tour bus driver in Hawai'i, had been able to tell him as they drove to the airport. And he had never before set foot in a sumo ring.

Five years later, against the...