Oba Ichio (1899-1959) enthusiastically practiced Judo and Kendo during his studies of foreign languages in Osaka and later at the Meiji University in Tokyo. Having finished his studies, he started training to become a diplomat.

During those years in Tokyo, he came in contact with Uchida Ryohei and the Kokuryukai (Black Dragon Society) and also with Nakamura Kichio, a leading member of the Kokuryukai and the forty-second soke of Takeda Ryu since 1911 after having been trained in the Genyosha by Takeda Tadakatsu, the forty-first soke of Takeda Ryu. Although Oba had never seen Aikijutsu before, Nakamura Kichio already recognized his talent during his first training session and it did not take long for Oba to become Nakamura’s favorite pupil and eventually his personal assistant. In 1935, Nakamura died and Oba became his successor, the forty-third soke of Takeda Ryu.

After World War II, the Americans prohibited all budo activity in Japan. Life had become difficult for Oba in Tokyo, so he and his family returned to Wakamatsu in autumn 1945. In 1946, he already began teaching Aikijutsu secretly in a little hut provided by his brother, with whom he lived at that time.

Despite the difficult circumstances in those years after the war, Oba succeeded in building his dojo on Yagura Mountain at the end of 1948. In addition, Oba often went to Tokyo to persuade other budo sensei to cooperate in a project for the revival of the Japanese martial arts. For this purpose he founded the Nihon Budo Renmei, and soon more and more schools (including Kashimashinryu, Jigotenshinryu, Sentoryu, Shindo-Musoryu, and Yamatoryu) became members of this organization. Beside this activity, Oba was also successful in teaching Takeda Ryu Aikijutsu in Tokyo. This enabled him to build the Seibuden dojo in Setagaya in 1953.

Oba died unexpectedly in the year 1959 without having named a successor, bringing the original line (genryu) to an end. In spite of his untimely death, Takeda Ryu has survived to this day thanks in large part to one of Oba’s later pupils, Nakamura Hisashi, who continued teaching Takeda Budo. His school, Takeda Ryu Nakamura Ha, became the starting point for the foundation of further Takeda Ryu branches and organizations.