They do like each other. Koreans love Japanese food and many Japanese also like Korean food. They watch TV shows from each other. Many TV shows are often just translated versions from the other country.

It's actually the politicians who want the people to have enmity to each other and some people are vulnerable to the propaganda. The existence of the North Korea regime and their history of kidnapping Japanese people also don't help. Much of their economic strength also overlaps, so there's competition as well.

If you still don't understand, think about close European countries. They probably get along just fine, but Brexit happened..

Oh yeah, I understand. That's why I brought up the last part. Germany did a relatively good job after the war of apologizing for its warcrimes and rooting out the toxic culture that led to them. I was trying to describe the gravity of the crimes that happened during the war with that comparison, less so the modern day feelings.