I was thinking of suggesting Yumi and the Nightmare Painter. It's a very chill book mostly about two people from very different worlds forced to explore the others' world and try to understand them. It's so chill that
Spoiler
the monster hunters (Midnight Painters) are more similar to postal workers than Warriors. They're important, but work a safe job that pays poorly.
It was inspired by Final Fantasy X and the movie Your Name.