Detective Story (2007)

Raita, a Japanese businessman, just moved into an apartment building where his next-door neighbor is another guy named Raita. But as a private detective, what that other Raita does couldn't be more different from a humble businessman's way of life. One night, in the beginning of a bizarre series of murders, one of the private detective's clients is killed and has her liver removed. The next victim has her kidneys removed, and the third her lungs. The two Raitas follow the clues and meet an eccentric painter, one whose paints are rumored to be made with human blood and organs...