Why do alot of China and Japan hate eachother?

[jtsunami]

Because Japan occupied parts of China, tortured people and used chinese women as sex-slaves. Check out the story of Manchuria.

CD

Unit / Squadron 731 and how the Japanese experimented on the Chinese people in their country while they occupied it.  Murdered around 400,000 civilians. 

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

Part 1 of 5 very interesting documentary on the place.

jt

[jtsunami]

Also another bit of history, when the US won the war, they found out and found the leader of the facility and the people responsible.  They did not prosecute them for war crimes, instead they gave them a deal that if they handed over there information they have collected on their human experiments they would go free, this is because most US scientists where do eager to gave data like this cause in the US they weren't allowed to do these experiments.

Later on in 1951 - 1953 the leader of the facility was on the front lines with the US in the Korean conflict, that was when they started to use chemical weapons against the Koreans as well.  US is not as innocent as you think.

jt

[jtsunami]

Another good video, shorter version shows more pictures.