The newly discovered materials also record the mandate issued by the Japanese troops to Chinese people, ordering them to catch mice for experiments. Some 20,000 mousetraps were distributed among the people, who were ordered to catch 450,000 mice. This large-scale mice-catching campaign was aimed at conducting research on how to spread plague. Aside from written materials, some audio recordings, which contain the accounts of the relatives of some members of Unit 731 and other forces, reveal Japan's heinous bacterial war crimes, says Yin Huai, director of the Jilin provincial archives administration.

In addition to the newly discovered materials in Jilin, other materials found abroad also show the scale of Japanese atrocities, especially those committed by Unit 731, in China.

Unit 731 also launched bacterial attacks against the former Soviet Union. According to Yang Yanjun, a researcher at Harbin Institute of Social Sciences, Unit 731 waged at least four such attacks against the Soviet Union in the 1939 Nomonhan War. Yang based his conclusion on a detailed study of the oral confessions of some Japanese prisoners of war who were involved in the attacks and other historical documents.

But even such solid facts do not deter Japanese right-wing forces from still denying that Unit 731 was nothing more than a sanitation team that operated behind frontline Japanese troops, and virtually nothing is mentioned about it in the country's history textbooks. In fact, many of the scientists involved in Unit 731 went on to have successful careers in politics, academics, business and medicine.

Shockingly, despite pledging of peace and vowing to have friendly ties with countries that suffered Japanese atrocities, Japanese Prime Minister Shinzo Abe seems to have a special liking for "731". In May 2013, Abe, smiling and giving the thumbs-up sign, posed for a photograph standing in the cockpit of a T-4 training jet, emblazoned with the number 731, at a military base in Japan's Miyagi prefecture.

This provocative act infuriated Chinese, Russians, Koreans and other victims of Japanese brutality before and during WWII and has left them wondering how far Abe and a Japan under his leadership will go to deny history.