In another romanized text by Nanbu, 横文字綴土佐日記 (https://t.co/qvTBpOMzkh), there are also some instances of "zyi" (as pointed out in https://t.co/y9v7YClq4k) as well as of "syi" and "tyi". Maybe there's even more; one might expect dyi in parallel to tyi, for instance. 3/ https://t.co/A6zhK23fYY