@Add1152000 : They still hate Japan for the atrocities of WW2 that Japan refuses to apologize for, or even acknowledge, or teach their youth about.
As to the rest of Asia, China has a State-level hunter, so they are "fine", and the Giants would have to thin out to leave Japan which would make them easier to hunt down. But Korea is not at risk yet, and Jin-woo would go after any that land on Korean soil for the EXP (which is pretty much the major reason he is considering going to Japan).