The reason for the misconception is assumed to be that both Mitsunari and Yodo-dono were from Omi, but the Ishida Family was a local ruling family that had an adversarial relationship with the Azai clan.
これは両者が近江出身ということからイメージされたものと推測されるが、三成の石田家はたしかに近江の土豪だが浅井氏とは敵対関係にあった。