Blind Exploration Rosen: the Sorrow of the Snowfield

During the Republic of China, there was a myth circulating in Shanghai - blind detective Rosen, who never solved any case. It is said that no matter how long it takes and no matter how bizarre the case is, as long as it is in his hands, it will eventually be solved smoothly. However, no one knew that the reason why he, who was blind, became a detective was to fulfill his mother's last wish and find the father he had never met...