and For the audience at home: https://duckduckgo.com/?hps=1&q=hoarded+Japanese+chalk&ia=we...
https://news.ycombinator.com/item?id=9723202 ("Mathematicians Are Hoarding a Type of Japanese Chalk", 109 comments)
https://news.ycombinator.com/item?id=19718287 ("Mathematicians are hoarding a type of Japanese chalk (2015)", 123 comments)
https://news.ycombinator.com/item?id=20237878 ("The Chalk Market: Where Mathematicians Go to Get the Good Stuf", 118 comments)
https://news.ycombinator.com/item?id=9770017 ("Hagoromo president explains why he closed down his beloved chalk business", 110 comments)
All the comments here attributing Japan's ability to have a chalk factory to basically Orientalist culture reasons are disappointing.
(In most of the reasons Japan and America are different here, America is the weird place, not Japan.)
and For the audience at home: https://duckduckgo.com/?hps=1&q=hoarded+Japanese+chalk&ia=we...