I read it a few years ago and was meaning to buy it, but promptly forgot. Lately I’ve been thinking about it.
It’s by a Japanese author, and I believe it’s a translation from the Japanese. It was published within the last ten years. The title is something like “The Mechanical Hummingbird” or “The Clockwork Finch” - some kind of play on a robotic bird. It’s about a man who’s wife leaves him, and he ends up talking to a young girl (I think) who lives near him. At one point, he finds himself trapped at the bottom of a well. I think the young girl eventually saves him.
I did some Google searches, but they were pre-caffeine and nothing’s coming up.