Thoughts + impressions *SPOILERS*
I'm a fan of Kiyoshi Kurosawa, and I love his film "Cure". "Retribution" reminded me of "Cure" and "Kairo" a lot, in its themes of isolation, loneliness, etc.
There are 2 shots/scenes in this film that reminded me a lot of the 1965 film "Repulsion", directed by Roman Polanski and starring Catherine Deneuve. One involves the wall splitting apart. The other is when the lights go out in the detective's apartment, and as he walks past a mirror you catch a glimpse of the female ghost in red in the mirror. In "Repulsion", there is also 'wall-splitting-apart-with-a-crunching-sound' action, and a scene where the leading lady moves a closet door which has a mirror on it and you catch a glimpse of someone in the mirror. I wonder if Kurosawa has seen "Repulsion" and likes it and is paying homage to it.
The reason given for the saltwater connection was interesting. Why saltwater and not regular water? I believe it is actually not merely saltwater, but seawater. The cause of death is water from the sea, which is reclaiming the land from human beings/civilization.
When the movie showed the female ghost in red flying away into the sky, it kind of took me out of the movie because I thought it looked so unintentionally funny.
I love it when Kurosawa does one of those long takes where a ghost may or may not be in the background of the shot.
I had a feeling that the detective's girlfriend existed only in his head, so when she turned out to be dead, I wasn't surprised, but that didn't make it any less sad to me.
It seems to me that in "Cure", "Kairo" and "Retribution", Kurosawa is criticizing social/cultural values in Japan, where people probably don't open up easily or very much about their personal lives and problems to others who may be able to provide some form of help or support. In these films, as a result of this "alone in a crowd" type of isolation, people start to fall apart at the seams and their minds begin to unravel. No one is exempt, not even those whose professions are to try and understand the human mind. The therapist in "Retribution" is somewhat cold and detached from his patients, and begins to fall apart towards the end of the film. In "Cure", didn't the detective's psychiatrist/psychologist friend fall apart too?
The more technologically advanced our communication devices, the more isolated we become. The bigger the city, the lonelier the souls. In the march of progress, those who are left behind are trampled upon and forgotten. To me, Kurosawa is pointing out that if our socio-cultural values don't become as advanced as our technology and infrastructure, the result will be human extinction.