The introduction to my edition says that the third part of this book was initially its own thing, and that makes a lot of sense. The first two parts of the book offer a kind of nest for the last part of the narrative.

An intergenerational story, which seems to be a trend in the 20th Century Japanese fiction I've read. Bleak also...kind of another trend. I have tended to link both of those things to WWII, but this one was published in 1914, so that theory doesn't hold up.