Kim Joon-myun's novels recommended for his rebirth included " White Night Journey,"" The Cross of Nothingness,"" Farewell," and so on.
The female lead of "Yixing Yiyi, Let's Fall in Love" was Kim Jong-in's younger sister. It was an exo doujinshi novel. I hope you like this fairy's recommendation. Muah ~😗
It's definitely not appropriate. Caricaturing any leader can be disrespectful and may cause diplomatic or international issues.
The North Korean leadership is mainly known for its dedication to the country and its people. While Kim Jong Un is married, North Korea doesn't promote this in the form of a 'love story' as Western tabloids might do. Their relationship is part of their private and family life within the context of North Korea's values and society.
I'm not sure which novel you're looking for because you didn't provide enough information. If you can provide more background or keywords, I will be more than happy to help you find the relevant novels.
I haven't come across 'bts x kim jong un fanfiction'. Fanfiction often focuses on fictional scenarios between individuals within a similar realm such as two entertainment personalities or characters from the same fictional universe. BTS is in the entertainment world, and Kim Jong Un is in the political world. So, it's not something that would likely be a mainstream or even a common fanfiction concept.