However, Japan has more than its fair share of far-right fruitcakes who deny everything, and in both Korea and China politicians have found Japan to be a convenient whipping boy whenever they need a distraction from domestic problems.
They elected a far right "fruitcake" to the post of prime minister.
At this point, I'm not even sure who to vote for anymore.
> In October 2006, Prime Minister Shinzō Abe's apology was followed on the same day by a group of 80 Japanese lawmakers' visit to the Yasukuni Shrine which enshrines more than 1,000 convicted war criminals.[57] Two years after the apology, Shinzo Abe also denied that the Imperial Japanese military had forced comfort women into sexual slavery during World War II .
This is from your link.
https://en.wikipedia.org/wiki/Treaty_on_Basic_Relations_betw...
So just citing that case isn't a full explanation of the enmity between Japanese and Koreans.
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..