The thumbnail history as I understand it is:
Kotaro Yoshida (1883 - 1966) was a journalist and member of the Black Dragon Society. He was acquainted with Sokaku Takeda and studied Daito Ryu with him (awarded Kyoju Dairi). He introduced Ueshiba to Sokaku in 1915. He was also adept at his family art of Yanagi Ryu and incorporated principles from Daito Ryu into it and taught both in Tokyo after the war. His son was Kenji Yoshida who became estranged from his father and moved to the USA before the war and later taught Yanagi Ryu to Angier Sensei. There are also connections with the Shindo Yoshin Ryu.
References would be Aikido Journal v.26 #2 and v.27 #1 and Daito Ryu Aikijujutsu by Stanley Pranin.
Hope this helps.
Doug Walker
Completely cut off both heads,
Let a single sword stand against the cold sky!