Kubo Sadaharu (久保貞治) was the 10th generation inheritor / head (Sōke​ 宗家) of Ryōi Shintō-ryū (良移心当流) and he passed the tradition down to the 11th head; Mori Hachiroemon (森八郎右衛門).

However, Kubo also taught Fujita Chōsuke Fumoto Kensada (藤田長助麓憲貞) 

(Kaku Kouzo ‘Nihon Bujutsu Budo Daijiten’ (日本武術武道大事典), Tokyo, - 2015)

Shinohara (2005) details this as follows:

“Ryōi Shintō-ryū (良移心当流) was put into the hands of Kubo Sadaharu (久保貞治), who held the position of Bujutsu Shihan (武術指南) to the Kuroda Han (黒田藩) feudal domain. 

Kensada (Fujita Chōsuke Fumoto Kensada - 藤田長助麓憲貞) learned from Kubo and gained fame in later years, while serving as a Bujutsu Shihan (武術指南) to the Osaka Magistrate's Office.

Shōbayashi Fujiwara Dōichi (庄林藤原道一)

(Learned from Kensada)….. and after consultation with the senior students  changed the name of the style to Jigō Tenshin-ryū ryū (自剛天真流). This followed the Jigō Tenshin no Maki (自剛天真之巻) that was in the manuscript written by Shōbayashi Dōichi’s own hand. However, except for the Sakkatsu (殺活 - killing & reviving techniques from Yōshin-ryū 楊心流), the instruction faithfully follows Ryōi Shintō Ryū Wajutsu (alternative name for Jūjutsu - 柔術) …..”

John J. O’Brien studied Jigō Tenshin-ryū Jūjutsu (剛天 真流柔術) in the Nagasaki foreign settlement and then returned to the U.S.A. There he taught Captain (later Colonel) Anthony Joseph Drexel Biddle Sr. (1874–1948), who in turn taught hand-to-hand combat to U.S. troops during the First and Second World Wars. Biddle published his techniques the unarmed combat book:  'Do or Die’.

When we look at the Ryōi Shintō-ryū Jūjutsu (良移心当流 柔術) technique: ‘Obi Hiki’ (帯引 - belt pull) illustrated in:

• Keikan Hikkei Kenpō Zuka (警官必携拳法図解 - Policeman’s Illustrated Kenpō Handbook) Edited by Tetsutaro Hisatomi (久富鉄太郎 編) Translated by Eric Shahan (2020)
• 'Hayanawa Kappō Kenpō Kyōhan Zukai Zen' (早縄活法拳法教範圖解全) by Iguchi Matsunosuke (井の口松之助) (1898)

and to the same technique in two versions of Biddle’s book:

• ‘Do or Die’ by Colonel A.J. D. Biddle (Copyright 1937, 1944)
• ‘Do or Die - A Supplemental Manual on Individual Combat’ by Lieut. Col. A.J. Drexel Biddle USMCR (1937)

it is easy to see the connection between Ryōi Shintō-ryū, Jigō Tenshin-ryū and via O’Brien to Biddle techniques.