This was a very good read all around! The story idea and character choices made things even more interesting as the novel went on. The white-on-black handdrawn portraits add a lot (the pen continues to get its glory, heh), backgrounds are chosen well, and the music complements the scenes. (I'm very intrigued by the excellent use of MuseScore 4.)
Some pieces of writing feel like they might get lost in translation, but it doesn't get in the way of the story. In fact, the cryptic feel actually adds to it in its own way.
Overall, I can see that you put a lot of work into this, and it shows. Well done!