This movie is adapted from the 1947 novel "Villon's Wife" by the Japanese writer Dazai Osamu. It is said to be semi-autobiographical.
The train line that is seen in the movie is the Chuo train line that runs from Tokyo station to the Western part of the Tokyo area. The bar is at Nakano station and the Otani homestead is at Musashikogane station.
The place where Otani and Akiko try to commit a lovers suicide is in the Northern part of Gunma prefecture in the Tanigawa area. He is taken to the Minakami police station afterwards.