Over the past four years, the Japanese government has spent at least 350 million yen on drugs, scopes and syringes to strike down tuberculosis in China, where there are 4.5 million active cases.

Supply packs note that the contents are paid for by a Japanese government grant, so patients know where the unexpected donation has come from. Media in tuberculosis-affected areas also cite the source.

"One of my colleagues met a patient from a rural area, and my colleague says some of the patients thanked Japan," said Satoshi Nakamura, a program manager with the Japan International Cooperation Agency in Beijing.

But China-based Japanese officials are still beleaguered by widespread Chinese hostility over lingering World War II issues, even as they aim to tell locals more about the TB program and other things contained in the 25-year-old official development assistance package.