Although there is a story about Kinemon OKANO and Otsuya (mentioned later) explaining how they acquired the map, Terasaka's diary stated that 'it was through a member from Kira's side.'
この絵図面入手経路について岡野金右衛門とお艶の逸話（後述）が生まれたが、寺坂の私記には「内縁をもって入手した」としている。