When the Mori clan aligned itself with the Ukita clan that was a deadly enemy for the Mimura family, Nobunaga ODA took this opportunity to invite the family to turn against the Mori clan, but Chikashige insisted, together with the family's old retainer Takei clan, 'Oda is not trustworthy and it is too early to decide to turn against Mori and align ourselves with Oda.'
毛利氏が三村家にとって不倶戴天の宇喜多氏と結び、それを好機と見て取った織田信長が毛利家からの離反を誘った際、親成は三村家旧臣竹井氏などとともに「織田はとても信用できかねる相手であり、毛利と手を切って織田と手を結ぶのは時期尚早である」旨主張した。