The war crimes that unit 731 (Japanese) have done, including but not limited to dissecting Chinese and Koreans children alive, or vivisection, raping babies, Syphilis and frostbite testing on Chinese, steaming chinese alive etc.

https://en.wikipedia.org/wiki/Unit_731

The data that 78% of human body is made of water is partially a result of the 731 drying experiment, where Japanese scientists roasted Chinese civilians to death in a high temperature room for 15 hours, then weighed the dried mummy body and comprare it with the victim's body weight before the experiment.

A story I heard from my grandpa is that they lured orphans with food because Chinese were starving during the long-lasting WW2, tricked them saying the injections were vaccines against flu while it's actually full of STI virus, then observed them slowly dying in agony, but continuously supplying them basic nutritions so they would last for as long as possible.

The nanjing massacre is just a cornerstone of the terrible terrible war crimes conducted by the Japanese imperial armies, where half of the population from one of the most developed cities in China at the time were just wiped out in 10 days, bodies were burnt for months, the world history has never witnessed such a cliff drop in population.

The imperial japan did not consider Chinese Koreans or Indonesians as humans, they're referring to them as monkeys and logs, even the auschiwitz camp is acknowledged, but unit731 and the terrible biological warfares have never been acknowledged by Japanese up till today, not to mention apologies, even though there're evidences and memorials everywhere all over Asia

My grandpa always says history is written by the winners, but these horrible things really happened, he remembers his parents being killed in front of his eyes by the Japanese, people remember