If you loved Tetsuo: The Iron Man, try Tetsuo II: Body Hammer
A bridge between a film you've already seen and one most people haven't. Tetsuo II: Body Hammer has roughly 5.2× fewer votes than Tetsuo: The Iron Man — it's a deeper cut, not a mainstream recommendation. Here's what they share, and what the second one does that the first one doesn't.
What they share
Both films are directed by Shinya Tsukamoto, and they both carry the body horror, surreal mood tags, and they sit in Horror / Science Fiction territory. If that's the register that drew you to Tetsuo: The Iron Man, the second film will land in a comparable space — through a different lens.
What Tetsuo II: Body Hammer is
Neon drips from 7-Eleven windows; winter night hums with vending machines gone berserk. A white-collar ghost’s son vanishes into a chrome blur of extortionists. Tsukamoto’s molten limbs weld body horror to cyberpunk pulse—one perfect raw bolt of wrong.

