It is supposed that Hidekiyo was engaged in the study of protocols for military families, which is proved by Ninagawa family documents that contain a transcription of a record of the oral transmission from Hidekiyo as one of the documents about the protocol for military families.
秀清も武家故実に関与していたようで、蜷川家文書の武家故実に関するものには秀清の口伝本を書写したものがある。