I have come across some Chinese people (in real life and online) who vehemently hate Japanese people for what?

"they've done in the past." Aside from the fact that the Japanese government now supports and provide extensive financial aid to China, why is that these people do not hate British people? Britain did loads of horrible things during and before the Opium War, and after the war, they coerced the Chinese government to sign unfair treaties and kept people being addicted to Opium, not to mention that they took away Hong Kong under its hegemony. So why is this?