The mysterious book box from another time

Two years ago I found a box with novels in Japanese in a second hand store. 

I had no idea about the stories nor about the genre. The books had no covers and no short descriptions. Their publication dates told me that these books are from a different time which I have never experienced. Nevertheless, I took the box home and I started to read. 

Googling for the titles helped me in getting to know at least the genre of the author, but hardly anything about the actual plot. Basically, I didn't know what to expect. It was like walking on a path in the dark not knowing where it's going to lead me.

Most people decide the books they'll read based on the plot summary on the cover. At least that's how I operated not a long time ago.

The stories I read so far were odd and even funny. Some of them were love stories which usually not ended too well. Some of them were on crime investigations. In fact, detective stories were very popular in Japan. 

Prof. Hideo Kajiyama  from Shimane University investigated the origin of detective stories in Japan. And he found that it's surprisingly connected to the history of Japanese police. Right after the feudal military government, called Tokugawa shogunate, collapsed in 1868, the Meiji Restoration took place. During this period Japan opened up to foreign countries. In fact, Japan had been a closed nation for hundreds of years. The Meiji period allowed the entry of foreign influences and ideas into Japan which contributed to the establishment of the railway transportation or the police forces. As a matter of fact, Toshiyoshi Kawaji copied and applied the French police system to establish the police in Tokyo. New terms such as 'detective' and 'spy' had appeared and found usage in several pieces of literature (1). The Meiji period is the time where the genre "detective stories" came to life. Later on, after WWII, the genre "detective stories" was changed into a more general term which translates as (crime) investigative stories. 

I've decided to post some translated chapters of  books I read so that you can enjoy the stories together with me.

References

1) Kajiyama H., 近代日本文学の牽引車としての探偵小説──黒岩涙香と翻案小説, Source: https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=&cad=rja&uact=8&ved=2ahUKEwiD-4fCwvXvAhVBg_0HHYKKBrwQFnoECBsQAA&url=https%3A%2F%2Fci.nii.ac.jp%2Fncid%2FBA85921659&usg=AOvVaw00IR8rVZBVXf35Qfu0gf-Z