HARBIN, Sept. 18 (Xinhua) -- Over 70 years ago, Okawa Fukumatsu was awarded a sabre for his outstanding services in human vivisection during World War II.
Two years ago, in his wheelchair, the former Japanese soldier handed the sabre to Jin Chengmin, curator of the Exhibition Hall of Crime Evidences of Unit 731 in northeast China's Heilongjiang Province.
The sabre had belonged to Shiro Ishii, commander of Unit 731, a top-secret biological and chemical warfare research base established in Harbin as the nerve center of Japanese biological warfare in China and Southeast Asia.
Since July, the one-meter-long sword has been on display in the museum as evidence of the Japanese unit's crimes against humanity.
In 2008, Jin flew to Japan to obtain evidence from former Unit 731 soldiers. He arranged a meeting with Fukumatsu but received a call from his family canceling it just moments before his arrival.
Jin was frustrated, but he did not want to give up. On his way back he called Fukumatsu to make another plea. Fukumatsu agreed to meet but made him promise not to ask anything about Unit 731.
To Jin's surprise, Fukumatsu talked about his time at Unit 731 during the meeting - telling the secrets that Ishii ordered him to "take to the grave."
In a video recorded by Jin, Fukumatsu said he was recruited by the Japanese army in 1941 when he was a student at Waseda University. He was soon dispatched to China as a "military surgeon."
Fukumatsu said he was ordered to perform human experimentation. When he refused, his meals were stopped as punishment.
"I gradually became numb. I operated on two people a day, and that increased to five people a day as my assignment went on," he said.
"Dissecting a body of a comfort woman in front of a crying child, poisoning a toddler after freezing him in ice and snow... I lost count of how many 'maruta' I experimented on. I spent almost all of my time in the dissecting room," he said.
"Maruta" was the code-name for the human experimentation project. In Japanese the word directly translates as "wood that has been skinned" or "logs," which is how the test subjects were referred to. At least 3,000 civilians and prisoners of war from China, the Soviet Union and Korea perished at the hands of Japanese scientists.
The retreating Japanese blew up the base when the Soviet army took Harbin in 1945. However, the evidence and guilt were not so easily destroyed.
At an international symposium on war and medical ethics in 2007, Fukumatsu attended as a witness, testifying to the atrocities of Unit 731.
As the two men became acquainted, Fukumatsu revealed his possession of the sabre. He allowed Jin only to watch from a distance and take no photos.
During the two meetings that followed, Jin persuaded Fukumatsu to let him take photos and videos of the sabre. In the winter of 2015, with the help of Japanese friends, Fukumatsu finally agreed to donate the sabre as evidence.
Monday marked the 86th anniversary of September 18 Incident, regarded as the beginning of the Japanese invasion. Illuminated by the light of the display cabinet, the sabre shines with a chilling lustre, reminding visitors of inhumanities committed in the past.
