Mad Detective = MPD Psycho ?
See Takashi Miike's odd but not exceptional tv miniseries "MPD Psycho", and the exceptionally *good* manga of the same name on which Miike's series was based.
From the characters to some of the dialog (mainly from plotlines in the manga that weren't adapted in the miniseries), Mad Detective seems clearly inspired by the detective with multiple personality disorder (the "MPD" in MPD Psycho) who tracks down serial killers.
So for that reviewer that was talking about the 'losers' in Hollywood ripping off THIS movie in a couple years, remember there aren't that many really new ideas: just a few you don't know about yet.
(And before anyone gets their panties in a wad - I'm not badmouthing Mad Detective here, unless you're the sort of zealot that needs to believe it's original in order to feel that it's good. Then take it how you want.)
You talkin' to me?
http://www.eddieoffermann.com/blog