For example, Bunei TSUNODA described as follows (in 'A younger sister of Yoritomo' "Ocho-no-meian" (The light and dark sides of dynasties) (published in 1975)): The description in "Azumakagami" that she died at the age of 46 was an error and should be 36 correctly because it is unnatural to die from hard labor at the age of 46, and he follows the age written in "Heiji monogatari."
例えば、角田文衞（「源頼朝の妹」『王朝の明暗』1975年）は46歳での産褥死は不自然であり、『吾妻鏡』に書かれた享年40六（46）は30六（36）の誤記で、『平治物語』に書かれた年齢に従うとしている。