Well, that's one set of atrocities I don't recall ever knowing about.... there was a movie based on the events released last year, here's the trailer:

731 - Official Trailer | Starring Wu Jiang

"Director Zhao Linshan (The Assassins) directs 731, a horrific tale of human corruption and depravity set inside the notorious Japanese Imperial Army Unit 731.

Prisoners are kept and used for gruesome and torturous experimentation for the purpose of developing bacterial and chemical weapons.

Wang (Wu Jiang) is a prisoner assigned as an interpreter for his fellow captives; through his eyes, we see this harrowing story of suffering and survival."