Yes, this is one of the issues, traveling abroad, which I want to do.
There is no way she wants the North Korean passport. Getting a South Korean passport requires a family register similiar to what they use in Japan, so really, the easiest would be for her to get a Japanese passport.
With the Zainichi, there is a lot of pride involved in their nationality, which is completely understandable but does complicate things.
Now regarding marriage in Japan, is it true that you need parental consent?