An episode that a monk in Tang sent a letter addressed to Michizane by a Shiragi merchant, has been also written in the proposal for stopping Japanese envoys to Tang Dynasty China ("Kanke bunso" [an anthology of Chinese-style poetry by SUGAWARA no Michizane]) that reported to the Imperial Court by SUGAWARA no Michizane.
また、菅原道真が遣唐使廃止について上奏した「請令諸公卿議定遣唐使進止状」（『菅家文章』）にも在唐中の僧侶が唐の商人に道真への手紙を託したことが記されている。