"http://www.cbc.ca/news/arts/japanese-vets-admit-on-film-to-nanjing-atrocities-1.889895"
Do you really believe all things because a vet says them? One of the leftist strategies has long been false accusations using the testimonies by so-called vets or traitors. Every country has such people as "testify" to the war crimes thereby. If their evidences are true, they must explain why the official report by Nanjing Safety Zone confirmed the population of the city was 200k and that 2 days after the end of the alleged massacre was 250k, and where the holes of bones of 300k are.
Regarding the site of your link, it deals with the film created by a leftist activist.
The testimonies of soldiers are quite disputable because one soldier said he was born in 1926. It means he was 11 y.o. when the massacre happened. All the other soldiers turned out to have used pseudonyms and pen names in their testimonies, which prevent the researchers from checking their actual words.
Even if the testimonies are true, it follows that they were very lucky persons that could continue to repeat the criminal activities strictly prohibited by military laws while avoiding the arrests by gendarmes.
See the smiling faces of children of the city who came to soldiers to play with them.
https://www.youtube.com/watch?v=_Tb7QSzSnug
Is there possibility that children were ready to come to the persons who are committing murders and rapes?
Use your common sense if you have.