The Wakisaka clan was formerly related to a nonhereditary feudal lord, who applied for the rank of hereditary feudal lord, i.e., applied to the goverment for raising of the clan from a nonhereidtary feudal lord to a hereditary feudal lord, but there was a custom that prevented the descendants of nonhereditary feudal lord family from being appointed to an official position in the Edo bakufu (Japanese feudal government headed by a shogun).
脇坂氏は元外様大名であり、入譜代、つまり外様から願って譜代格に直してもらった家柄ではあったが、外様の家系は幕府の役職には就けないのが慣例であった。