The Biwa Mansion 枇杷殿 was the residence of Minamoto no Nobumitsu 源延光, who was the father-in-law of Sanekata’s uncle and guardian, Naritoki. The Eiga Monogatari tells us that it was, in fact, Nobumitsu’s wife, who brought up and cared for both Sanekata, and the sons of Naritoki.