Originally Posted by
jib71
That's a start.
When you get the certificate, double check that the sample collection method is an *exact match* for one of the MHLW's specified methods.
Ditto for the testing method.
https://www.mhlw.go.jp/stf/covid-19/....html#h2_free5
Perhaps things are a little less pedantic than they were a year or more ago, but folks were turned back at the border because their documentation left agents less than fully convinced that the test had been conducted according to a specified method of sampling or testing.
The easiest way it to have the testing center fill out the government form themselves and put their stamp on it in the "name of medical institution" area. That way it looks very official. Labs that are familiar with travel to Japan will have the form on hand and do it themselves, but if not you can print it out and take it with you, and ask them to fill it out.
You can download the form here (under the "format" section)
https://www.mhlw.go.jp/stf/covid-19/border_test.html