I do not think very highly of the Japanese police.
1. I have been arrested everytime I've been in Kyoto for loitering in the station. 5 minutes is apparently too long for me to be standing there.]
2. A story I heard recently in Chiba, when neighbours phoned the police to complain that there were screams & thuds coming from one of the apartments. When the police came round a man answered the door covered in blood. The police then asked if they could come in (they apparently had a warrant) he said no, the place is a mess. They went away.
I believe it could be true.