I read about Toshikazu Kawaguchi's novel Before the coffee gets cold in an article about "newer" time travel books. The premise of the novel is that if you sit in a certain seat in a certain cafe in Japan you can time travel to meet someone who has also been in the cafe at some point in time. There are a bunch of rules associated with the time travel. You must remain in that seat, you can only meet someone who has been in the cafe, you have to stay in the seat, you can't change the future, and you have to finish drinking your coffee before the coffee gets cold. Imagine the pressure!
I listened to the audio book. Some of the language was sort of flat but I wonder if that's because I was listening in translation. There were basically 4 chapters, each basically a little story on its own. Culturally, I'm not sure that these stories could take place anywhere other than Japan. Or at least they probably could not happen in the United States.
The first story was about a young women feeling like her boyfriend chose his career over her. The second story was sadder about a married couple. The wife is a nurse and the husband has early onset dementia. That story was emotionally difficult to listen to. The third story was about the estrangement between two sisters. And the final story was another bittersweet story in which the wife of the cafe manager goes into the future to see how their lives evolve.
There was one character, the woman in the white dress, the ghost in the white dress, that I wish we'd learned a lot more about. That was left hanging.
If you're interested in reading a short, different time travel book, about human nature and that ends with some lessons, this might be a book you'd enjoy.