East Asian geopolitics is easy to understand, everyone hate each other.

However, Japanese hatred of Chinese and Koreans is the weakest.

Koreans hate Japan for their brutal colonialization, they hate China for fighting off the American invasion of North Korea.

Chinese hate Japanese for the genocidal war against China, we dislike (no necessarily hate) South Koreans for their appropriations of traditional Chinese culture (without any form of acknowledgement).

Japanese hate Koreans because they feel guilty about their colonization of Korea.
They hate China for because they feel China might one day take revenge for the crimes Japan committed in China.

Japanese racism against Chinese and Koreans is NOT a fringe belief, it is the norm for Japanese to worship whites while hate on other East/ Southeast Asians.