Referring to records of Mandokoro, the Office of Administration, and Monchujo, the Office of Inquiry, in the Kamakura bakufu and even diaries of the Kamakura bakufu in Kyo, they thought seriously about the question raised by Katsuro HARA and the criticism of the historical materials, revealing that Azuma Kagami wasn't a chronological record as had been originally thought, and was instead compiled in later ages, which means that it contains many errors and misrepresentations in writing.
二人は、原勝郎の問題提起、史料批判をさらに押し進め、それが当初思われていたような逐次記録ではなく、鎌倉幕府の政所や問注所の残る記録のみならず、京の鎌倉幕府の日記類まで参照しながら後世に編纂されたものであり、またそのなかには多くの誤りや曲筆があることを明らかにする。