I found all the books of Napoli's I read really problematic in one way or another, and just about all of them seem to be miserable. :/

Nahoko Uehashi's Moribito books look like if there's a romance subplot, it's very minimal; I can't tell from the plot summaries and I haven't read the ones that have been translated so far. They appear to focus primarily on the main character and the child she has to protect.

I'm going to have to keep an eye out more carefully; I'm not bothered by well-done romance subplots and don't always remember them when I think about a book, but I am am frustrated about how many romance subplots are badly-done and/or derailing to the story and wish romance weren't shoehorned into every story.