Describing kuzushiji ("broken characters") as a "writing system" is a bit much, I'd liken it to a cursive script. Not that this diminishes the importance of ML here, since anybody who's tried to read historical English documents will know that these can also be pretty incomprehensible to the untrained eye:
https://www.nationalarchives.gov.uk/palaeography/doc5_popup/...
But as ever, Japanese ramps up the difficulty because there are thousands of characters instead of 26 letters to deal with.