BTS’ work have clearly been inspired by The Little Prince by Antoine de Saint-Exupery . This can be seen from the 2020 FESTA poster to the music video of Serendipity.
In addition, I believe that The Little Prince can be used as a guide to interpret the lyrics as we can easily draw many parallels from the book to the lyrics of some songs.
If you wish to read it, I have provided a downloadable copy below. Enjoy 🙂