I've seen some agencies interpret that the rule is for them to be "involved", and which are happy to receive a copy of the itinerary followed by daily check-in text messages on health status and confirming you are in the right city/hotel while in Japan.

My personal view is that the government wouldn't check/care, the same way they have must know some people "attended conferences/meetings/events" for one day and then vacationed for multiple subsequent days, over the past few months. If they didn't clamp down on those (for instance by issuing visas for the specific number of days of the conference program) they probably wouldn't start now.

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