Hideo Shimizu, a former member of Unit 731, the notorious Japanese germ-warfare unit during World War II, flew down to Harbin, capital of Heilongjiang province, on Monday evening to testify and expose the crimes committed by his unit during the Japanese invasion of China.

Upon Japan's surrender in 1945, Unit 731 tried to gun down all survivors and destroy all evidence of the atrocities they had committed. Yet they couldn't possibly wash away all the blood stains and the Exhibition Hall of Evidence of Crimes Committed by Unit 731 of the Imperial Japanese Army in Harbin, which is also where Unit 731 was once located, lists ample evidence collected from the ruins, survivors and all possible channels to show how Japan's then imperial army committed germ-warfare and other atrocities on human bodies.

By deposing and admitting to the crimes committed by Unit 731 on Tuesday, the 94-year-old Shimizu has defeated the Japanese right-wing political forces' efforts to deny all what happened.

Shimizu was just 14 years old and among the last batches of Unit 731 Youth Corps members sent by Japan to Unit 731 in Harbin almost 79 years ago. He is a living witness to the war crimes committed by his unit, including the cultivation of pathogens, human dissections and experiments on humans, a witness from the side of the tormentor. His testimony only solidifies the charges against Japan.

Before Shimizu, in 2005, Yoshio Shinozuka, another Japanese soldier who served in Unit 731, had visited the former site and apologized for the atrocities they committed. Some more soldiers have done the same in the past.

With the passage of time, there will be fewer survivors who have served in the former Unit 731 who are willing to visit the site and confess to the crimes and atrocities they were forced to commit. But that won't alter the fact that Japan committed untold crimes in China during its years of militant expansion, which are already permanently carved in history and left forever.