Well-behaved? They are taught to worship the emporer. I hear if they go in the military, the pretty ones are inclined to have been raped. It sounds like a truly messed up culture. It would be hard enough to deal with a woman from free South Korean culture because of how different the culture is. There is no telling how hard it would be to deal with a North Korean woman. There probably aren't many non-North Koran men out there who have experience who could tell you.
For US citizens, you'd have to jump through some legal hoops to get there legally. I don't know if they'd let foreigners marry their women and live there, either.
There is no way to date and marry a North Korean woman in North Korea. This can be done only outside of North Korea.
There are North Korean people living in Japan or Germany, fairly large communities.
There are many North Korean overseas workers in Russia and other countries, doing anything from construction to restaurant services.
There is also the border city of Dandong to meet North Koreans - but now economy is not nice there. The Chinese government wants all of them to be gone. Dandong is known for many North Korean living and trading there.
https://www.reuters.com/article/us-nort ... SKCN1C70PC
Further, there are also North Koreans in South Korea who made it over the border.
However even South Koreans have a lot of problems to deal with these people who have no idea about the world outside of NK.
They know nothing, even not how to pay for a bus ticket or how to use an ATM. Others are known not even to be grateful, expecting the South Korean government will give them a job, housing, food, medical care and so on all for free, they are not accustomed to apply for jobs and to work for a salary.
Language education is also a big problem, they do not understand about 30 to 40 percent of the language now spoken in South Korea.
Re-education in South Korea takes at least 3 to 6 months to be sure, the newcomer is not a spy and is willing to integrate.
South Korea is basically a foreign country for these North Korean people, they have to learn everything from the very beginning on.
Some do it, and they will change to another name and 'disappear' within the Koreans. However others are unwilling, even ending up in criminality.
Many South Koreans are totally against any unification, it might almost bankrupt South Korea in case of open borders. There are more than 25 million North Koreans vs. 50 million South Koreans, about 1:2. Opening to North Korean if ever can be only done in a one-way. Foreigners into North Korea but not in the opposite direction.