Motoyasu had a son-in-law called Zennosuke, who was the second son of the Iwaki clan, wealthy family of merchants and literature, and Zennosuke's son Motoichi HASHIO was a member of a branch family of the Konoike family ("Zenkiteki Shihon no Henshitsu Katei: Konoike Kenkyu no Issetsu" [The Process of Changes of Pre-modern Capital - a Study on the Konoike Family] written by Shigeaki YASUOKA, included in page 480, Volume 4 of "Osaka no Kenkyu" [Studies on Osaka] edited by Mataji MIYAMOTO and published by Seibundo in 1970).
元恭は能登の豪商文人一族岩城氏の、次男善之助を娘婿としており、その子箸尾元市は鴻池家の別家となっている（安岡重明『前期的資本の変質過程：鴻池研究の一節』、宮本又次編『大阪の研究』清文堂.1970年第四巻p480）。