'Grotesque' (2009) aka 'Gurotesuku'. Dir.  Kôji Shiraishi.

Kôji Shiraishi's spectacularly sadistic serial killer (Shigeo Osako) methodically captures a young couple, and no less meticulously puts them both through a cruel, outlandishly gruesome barrage of almost unimaginable torment. Stalin would have loved it! This wickedly exploitative J-Horror has a uniquely perverse quality that proves morbidly captivating, much like the proverbial catastrophic road accident, one can't quite bring oneself to turn away! Frankly, the director is only too plainly aware of the nakedly prurient nature of most horror fans, and knows that we will lovingly lap up every lurid, vomit-spattered second of it! Erupting with unrivalled brutality, agonizing levels of bloodthirsty depravity, and vividly photorealistic gore, 'Grotesque' recalls the infamous 80s 'Guinea Pig' series! I think it's quite safe to say that gifted director,Shiraishi most certainly doesn't wimp out with his gut-churningly visceral climax. Love hurts, baby!