Gleipnir 5

Dark, disturbing, sexy, and shameful, this new sci-fi action manga stars a dominating teenage girl searching for a sister who became a monster, and a submissive boy with the strange power to turn into a ragged but powerful beast, with a zipper down his back and a compartment on the inside just big enough to hold a human body. It's like Poekmon with a dose of S&M;!-- Publisher's description.