In 'Makura no Soshi' (the Pillow Book), there is an episode that begins with the phrase, 'there is no other quick-eared person like Okura-kyo (Minister of Treasure),' and it is said that 'Okura-kyo' referred to Masamitsu.
なお、「枕草子」には「大蔵卿ばかり耳とき人はなし」で始まる段があるが、これは正光のことを指しているとされる。