He and Sadayori ROKKAKU were tied by strong relationship as a master and servant, but after Yoshikata ROKKAKU inherited the family, Sadahide's power became more powerful and reversed this master and servant relationship, and he lent money to Yoshikata that was struggling against hard living because he was forced out of his castle by the Kannonji family feud in 1564, and he steadily secured a pledge of refund.
六角定頼とは主従の絆で結ばれていたが、六角義賢の時代からは主従の力が逆転してむしろ定秀の力のほうが上であり、永禄7年（1564年）には観音寺騒動で居城を追われて生活苦にあえぐ義賢に対して金銭を貸し、しっかりと返済の約束も取り付けたりしている。