I cant speak for the Tokyo area at all, but the stuff in Aomori was pretty weak.
I mean, that is where I started smoking and the only thing that happened was that everyone started laughing more. But that was it.
I got back to the states and had a joint and thougth someone had laced it with something, I was S T O N E D.
I got high, but never stoned.
MB someone else can speak about the large city scene.