Yoshimitsu Yamada was born on 17 February 1938 in Tokyo. His father, Ichiro, was an academic professor, and his mother, Michio, took care of his home. The father's family was related to Abe family and, when as a child Ichiro lost his parents, he was adopted by them.

The difficult situation of Japan during the II World War forced both families to emigrate to Korea during the forties, where they settled in Chinju, a small town, about 200 miles from Seoul. The Abe family head, Kazo, leased land there and run his own business, Ichiro Yamada went into mining business. They stayed in Korea until the end of war.

Ichiro Yamada’s cousin Tadashi Abe, had been practicing aikido since 1942. This coincidence undoubtedly affected the later life of Yoshimitsu. A just several years old Yoshimitsu has had contact with O-Sensei for the first time even before the trip to Korea during a martial arts presentation in Abe family home. This meeting made an unforgettable impression on him. He reminiscences, as if it were today: a nice, calm, elderly man O-Sensei seemed to be at first glance, become someone completely different on the mat - an uncatchable and mysterious master of martial arts.