Master Kodo Horikawa (1894-1980) was Born in Hokkaido, Japan. He began Daito-ryu Aiki-jujutsu training in 1914 under Master Sokaku Takeda and his father Taiso Horikawa who had a teaching license from Takeda.
He became a school teacher in 1917 and worked at various elementary schools in northern Hokkaido. Sokaku Sensei visited a school Horikawa Sensei was working at and remained there for several days transmitting to him the secrets of Daito-ryu.
He trained for 6 hours a day under Master Sokaku Takeda and received several important certificates from him in 1931. This included..
1 - Dairi Kyoju - 'acting instructor' in 1930,
2 - Hiden Mokuroku 'secret essence'
3 - Hiden Okugi Mokuroku 'secret essence of mysteries'
4 - Hiden Aiki Okugi Mokuroku 'secret essence of aiki'
The final certificate, the Menkyo Kaiden 'Daito-ryu master' was given to him by Master Sokaku Takeda many years later.
In 1950 he established the Daito-Ryu Aiki Jujutsu Kodo Kai in Hokkaido.
In 1974, for his long, distinguished service in the martial arts, he received the Eisei Meijin (order of eternal mastership), the highest title awarded by the Budo society.
He finally received permission to become a Shihan at the age of 37.
Morihei Ueshiba developed Aikido from his combat studies of Daito-ryu Aikijujutsu with Sokaku Takeda, and his spiritual studies with the Omoto Kyo and Onisaburi Deguchi.
Aikido focuses on harmony and non-resistance, leading to Success!
Sokaku Takeda taught Horikawa for many years, according to his body-type. Kodo was a short man 4'11", and Sokaku specifically told him that he...
needed to master Aiki because of his height.
He instructed him in mostly the Aiki principles, and his techniques came to be known as very subtle, effective, and strong. This is why his Kodokai style emphasizes Aiki over strength to execute high-level techniques.
Kodo Horikawa Sensei attached great importance to teaching on a one-to-one personal basis. It is said that he always told students about Sokaku Takeda, and explained the history and essence of the art of Daito-ryu Aiki Jujutsu in rest periods from instruction.
One of his top students was Seigo Okamoto who went on to found the Daitoryu Aikijujutsu Roppokai, which now has dojo's in Japan and abroad.
I personally have a dvd of Master Okamoto, and it has been a great help in my own aiki studies... highly recommended! More on Daito-Ryu Aiki-Jujutsu