Marebito (2004) on Netflix

Plot summary

Freelance cameraman Takuyoshi Masuoka takes his camera everywhere and cannot let go of a question: what does fear feel like? After watching a man named Kuroki push a knife into his own eye, he goes looking for the answer in the tunnels beneath Tokyo. There he sees pale, four-legged humanoid creatures that whimper like dogs, meets a homeless man who warns him about the deros, and listens to Kuroki talk about the underworld and The Shaver Mystery. Deep below he comes upon a mountain range and ruined city buildings, and there finds a young woman chained to a wall. Masuoka takes her home and calls her F. She will not eat, drink or speak, her toes are oddly formed and her teeth are sharp. He sets up cameras to watch her from his phone whenever he leaves.