Yoshikado was the immediate younger brother of MINAMOTO no Yoritomo, and according to "Keizu sanyo" (The Entire Compilation of Genealogical Tables in Edo Period), Yoshikado and Yoritomo were children of the same mother, a daughter of FUJIWARA no Suenori; however, it has not yet to be found a material of the same period which proves the information.
源頼朝のすぐ下の弟であり、『系図纂要』によれば母は頼朝と同じ藤原季範の娘とされているが、同時代的にそれを裏付ける資料は確認されていない。