More may of course be said, but the alleged 'isolation' of Edo-era Japan has been greatly exaggerated. See the answers to:

• Why did Japan decide to limit access of the country to foreigners? by /u/ParallelPain,
• Why was the Dutch republic still allowed to trade with Japan during Sakoku, even though no foreigner was allowed to enter the country? by /u/kieslowskifan, and
• How was the VOC able to get a trade relationship with Japan where other trading nations and companies didn't get access to Japan in trading? by /u/t-o-k-u-m-e-i.

And also thanks again to ParallelPain for compiling these links previously so I could copy-paste the whole thing again here.

This is just a very trivial complement.

Not exactly the "average" upper class persons, but a limited number of elites - such as the top of individual clans and some nobles - in fact shared an unofficially circulated copy of the report on what are at issue in the world from the Dutch Trading Post (officially submitted only to the Shogunate), called Oranda Fu-setsu Gaki ('hearsays from the Netherlands'(「オランダ風説書」))'. Some latest research in the 21th century focus on this type of documents.

• /u/ParallelPain mentioned this kind of reports before in: Were the Japanese aware of the 1st Opium war in China? If so, what did they think about it?
• I also posted a more detailed account of the document as a complement to Are there any contemporary Chinese, Japanese (etc.) sources on Russia's eastwards expansion, and what did they say? with the link.

Since the link I cited in the linked post above seems to be a bit difficult to refer to now, I attach a picture of one of such unofficial copies of the Dutch hearsay reports also to this post. The document in question is an unofficial copy of the document of 1854, narrating the Crimean War, the Ottoman Empire as well as the Taiping Rebellion briefly and found in the archive of the (pro-imperial) noble Sanjo family.