Germany's the exception, not the rule. Most countries's governments like nothing more than to behave as if their past transgressions never happened. And even then Germany has had no shortage of politicians who say "Germany has apologized enough".

Japan and South Korea signed an agreement in 1965 that was supposed to settle all financial claims.

https://en.wikipedia.org/wiki/Treaty_on_Basic_Relations_betw...

This agreement is about property claims, not about war crimes against civilians.

The agreement is about "property and claims" between the two states. Of course, individuals can and have sued various Japanese entities, some successfully.