荒野上的充气娃娃 (1967)

Kôya no dacchi waifu

Also known as Kôya no Dacchi waifu (Dutch Wife is slang for an inflatable sexdoll). A private detective is hired to find a woman who has apparently been murdered in a snuff film. It turns out the woman's not dead, but very much alive, and he gets sucked into a torrid affair with her that leaves him questioning his sense of reality.