The café, which is called Funiculi Funicula, is the novel’s sole setting. It is located in Tokyo, Japan. It opened in 1874 and has been operating continuously since then. Currently, it is owned by a man named Nagare, and the waitress is a young woman named Kazu. The café has several regular visitors, such as Hirai. The staff and clientele are all friendly people. The most notable aspect of the café is that, if a person sits in a specific chair in the café, they can travel through time. However, there are several constraints on the time travel itself. First, if a person travels to the past, nothing they do will change the present. If they change something in the past, other events will then change in order to reverse the effects of the initial change. Secondly, the person cannot rise from the chair during the time...