Round trip with multiple countries

I'm planning a trip from the US via Japan and Shanghai. My itinerary would be:
* Seattle -> Tokyo; stay a few days
* Tokyo -> Shanghai; stay less than 72 hrs
* Shanghai -> Seattle (with a layover in Tokyo)
This would all be on one ticket with ANA airlines.

Would this qualify for the 72 hour visa? Or would I have to go directly back to Seattle from Shanghai (without a lay-over in Japan)?