One great horrorfilm from the director of "Tetsuo".
Young policewoman Keiko is confronted with two horrible murders. It looks like suicide but both victims dialed the number "0" before they died. To find out what was happening she detects a mysterious man called "Nightmare Detective" who can enter dreams.
-- Sorry for the worse description. It's definitely worth wachting. :)
PS: If anyone wants to know, the child voice in the background says something like "Help me"