Chuck Waterman here.
RE: PCR tests in Michigan
There are “Urgent Care Clinics” in several suburbs of Michigan that give PCR tests with same day results for people returning to Japan from that state, even without US insurance . Mine cost a little over $100, but that was a much more reasonable price than many Japanese clinics. Check with individual clinics though - some don’t offer it though many do, and some are better than others about scheduling and some will even fill out the MOFA form!