Exte: Hair Extensions is a 2007 Japanese horror movie directed by Sion Sono.
An insane morgue night watchman named Yamazaki steals the corpse of a young woman which continues growing hair at an extreme rate. He harvests the hair and sells it at a local hair salon. However, the hair is cursed and begins taking control of all the people it’s used on. Meanwhile a hair stylist named Yuko must protect her timid niece Mami from these possessed customers as well as her own abusive mother.