Invisible Monster (2013)

Original title: インビジブルモンスター

Random street attacks have been occurring in a local industrial city. No similarities among the victims, no clues for a motive or the culprit's next move except for sightings of a large figure in a raincoat. On her way home, Nami encounters an attack in progess. She sees the killer eye to eye and is attacked. Tsukishima saves her in a nick of time which brings them closer. In the same city, Detective Shintaro Matsuyama is after the killer responsible for the attacks. He sees a similarity to an unsolved street attack in which his daughter was killer 15 years ago. The city becomes depressed as people are afraid of the attacks and those who try to bring justice. Nami's life grows gloomy along with her symptoms of PTSD, despite falling for Tsukishima. Then she discovers his past. Shintaro becomes emotional with revenge and begins to derail from his police work. The killer is on the loose again.