Hello, thanks for the answer. What do you mean? She's flying July 8th next month.

Transit passengers will only go thru security check. That is what I mean.

Your friend won't be able to do any sightseeing during the 10 hours but just stay airside of Haneda Airport. The transit hotel won't be available.

Thankyou so much for your help. A travel agent just e-mailed me saying 72hr negative COVID-19 test required before boarding transiting through Japan. My head hurts 😅. So just to confirm again. transiting through Japan doesn't require COVID-19 negative test? There's no mention of transit flyers anywhere on Ana, Jal, or US embassy in Japan.

https://jp.usembassy.gov/covid-19-information/

Maybe the airlines requires it. What airlines will she be using?

I think airnippon. I think airlines don't matter. I just think the travel agent isn't knowledgeable.

That website says

If you are transiting Japan to an onward international destination, you will not be subject to Japanese entry requirements, as long as your transit occurs within the same airport and no overnight stay is required. You will not be permitted to travel from one Japanese airport to another in order to board a connecting flight. Please note that Narita Airport does not operate 24 hours and you will not be able to stay in the transit area overnight.

So no pcr test required.

And Japan Airlines says

Travelers who are not entering Japan and transferring directly to a third country by transit, are not required to submit any documents and undergo PCR tests.

I am about to transit to Japan with a 11 hour layoever. Not leaving the airport , am I still required and register at MYSOS?