They weren't open as of last month, not checked recently.

This said, COVID cases are rising again around the globe (China and Hong Kong are particularly under pressure at the moment, and Europe will likely be in a couple of weeks), so I wouldn't plan long trips to Asia just yet.

They allow a few thousand people in every day (I think it's 7000 now or soon) with quarantine conditions depending on the country of origin. I'm not sure whether that includes tourists yet.

As of this month, the quarantine conditions are virtually gone if you’re vaccinated except for arriva from a few countries. But no tourist visas yet, and business visas need a compelling reason. Also note that the 7,000 cap includes returnees (both citizens and residents).

I’m in the UK and I received a Visit Japan advert the other day. No guarantee the spending on Instagram ads is joined up with the entry requirements but it seems likely.