Tetsuo: The Iron Man

Tetsuo is a movie starring Tomorô Taguchi, Kei Fujiwara, and Nobu Kanaoka. A businessman accidentally kills The Metal Fetishist, who gets his revenge by slowly turning the man into a grotesque hybrid of flesh and rusty metal.
A "metal fetishist", driven mad by the maggots wriggling in the wound he's made to embed metal into his flesh, runs out into the night and is accidentally run down by a Japanese businessman and his girlfriend. The pair dispose of the corpse in hopes of quietly moving on with their lives. However, the businessman soon finds that he is now plagued by a vicious curse that transforms his flesh into iron.