3 ideas
Kubo's lack of a job is one reason his walk through the city has no set destination, and his tram rides with no stop in mind suggest a life without direction. His drift is mixed, though: he goes to the station looking for company, and his walks also serve his work as a novelist, so the itinerary reflects his marginal position among other motives rather than mapping it alone.
Kubo's failing eyesight, deafness in one ear, headaches and imagined illnesses are not background detail. They are the filter that shapes what he notices, and his catalogue of ailments becomes a way of reading other people's bodies as diagnoses. Perception is shown to be physical and sick, so that looking at the modern city turns into examining symptoms, both his own and the city's.
The novella holds that the crowded commercial city, full of department stores, cafés, trams and fellow walkers, gives the isolated person constant contact and no connection. Kubo is surrounded by people yet speaks through fragments, silent judgments and missed encounters. Mixing with the crowd leaves him more aware of his solitude and of how far he is from ordinary happiness.