OK, above I said it was unlikely that there would be a larger quake associated with the M7.3. There was a M4.8 beneath the edge of Tokyo Bay 10 hours before the 7.3 far offshore. Everyone is worried about the subduction zones near Tokyo, and the M9 Tohoku quake likely advanced the time of a catastrophic quake there (I said "zones" intentially; I could be wrong but I recall that there are 2 different ones in that area, from a talk that I heard a few years ago, and from the tectonic map).

I doubt that the M7.3 has much affect on the Tokyo area faults, beyond a little jiggle from the seismic waves.

Chris