Tokyo Ghoul

Strange murders are happening in Tokyo. Due to liquid evidence at the scene, the police conclude the attacks are the acts of man-eating monsters, ghouls. College buddies Kaneki and Hide come up with the idea that ghouls are imitating humans so that's why they haven't ever seen one. Little did they know that their theory may very well be reality. Note: The prototype chapter won the Young Jump 113th Grand Prix award in 2010.