Nakakura was originally the top kendo student of Nakayama Hakudō. When Nakayama was asked to send a representative of kendo to Morihei Ueshiba's aikido dojo, he appointed Nakakura to the role. Nakakura married Ueshiba's daughter Matsuko and was legally adopted into the Ueshiba family, taking the name Morihiro Ueshiba.
Nakakura was impressed with Ueshiba's martial skills (particularly after his adopted father was able to fend off a simultaneous attack from both Nakakura and the fencing expert Junichi Haga), but disagreed with Ueshiba's Oomoto-kyo beliefs and left the family after a few years. His role as heir to Ueshiba's art was taken by Ueshiba's birth son, Kisshomaru.
- John Stevens (16 February 1999). Invincible Warrior. Shambhala. p. 48. ISBN 978-0-8348-3016-5.
- Thomas A. Green; Joseph R. Svinth (2010). Martial Arts of the World: An Encyclopedia of History and Innovation. ABC-CLIO. p. 134-135. ISBN 978-1-59884-243-2.
- "Do you know the story? "O-Sensei's Adopted Son and Heir Apparent"". Aikido Journal. Aikido Journal. Retrieved 30 March 2017.
- "Nakakura sensei". All Belgium Kendo Federation. Retrieved 30 March 2017.