Ohshima was born on August 6, 1930, in Japan. By the age of five, he had already begun learning martial arts. He studied sumo from the ages of 5-15, kendo from 8-15, and judo from 9-13. Recalling an episode from his youth, Ohshima said, "One day I was going to Tokyo. This group was beating one young student because he was a quiet boy, but something he pushed with his elbow. And this was a ridiculous reason. But these guys were beating this young boy - same age as me, fifteen or sixteen. I got so mad. Mad, because person next to me said, 'Don't go, you get beat up.' I was ashamed of myself. I knew this was injustice. Why couldn't I put myself out there? I could be beaten up, but I could stand it. But I just sit there and overlook. I say to myself, 'Alas, how I am a coward guy.' I knew somebody was getting beaten up, but I couldn't help him. Therefore, when I was practicing karate, every time I asked myself, 'Are you ready to put yourself into something that you believe is justice?'".
Karate career
Ohshima began studying karate in 1948, while a student at Waseda University. There, he trained under Shotokan's founder, Gichin Funakoshi, and later became captain of the university's karate club in 1952. That same year, Funakoshi personally awarded Ohshima the rank of 3rd dan black belt. Ohshima's seniors at the club also influenced his development in karate; they included Shigeru Egami, Toshio Kamata-Watanabe, Hiroshi Noguchi, Tadao Okuyama, and Matsuo Shibuya. It was also during this period that he befriended Mitsusuke Harada, who would go on to become a pioneer of karate in Brazil and the United Kingdom. Ohshima was a member of the Japan Karate Association in its earliest days. In 1955, Ohshima travelled from Japan to the United States of America to continue his tertiary studies in economics at the University of Southern California. In 1957, he founded the first university karate club in the USA at the California Institute of Technology. That same year, Funakoshi promoted Ohshima to 5th dan - the highest rank awarded by Funakoshi, and the highest rank in the SKA system to this day. In 1959, he founded the Southern California Karate Association. It was around this time that Ohshima invited Hidetaka Nishiyama to take charge of his karate students in the US, as he was planning to return to Japan following completion of his US university studies. The arrangement did not work out satisfactorily, and was to be a source of bitterness between the two masters. In the end, unhappy at Nishiyama's actions and the direction being taken, Ohshima settled in the US and continued teaching there. Due to the SCKA's growth across the US, it was renamed Shotokan Karate of America in 1969. Black Belt magazine selected Ohshima as its Japanese Instructor of the Year in 1968. During the mid-1970s, Ohshima lived near Griffith Observatory in Los Angeles. His main occupation at this time was teaching physical education as a member of the faculty at Caltech. Ohshima has written two books on karate - Shotokan Karate of America: The first twenty years and Notes on training - and also translated Funakoshi's Karate-do Kyo-han into English. He also demonstrated the nineteen Shotokan kata for Funakoshi's book. In 1980, Black Belt magazine announced Ohshima as the inaugural recipient of its Publisher's Award. The award recognized "the role he has played in the development of karate in the United States and the world over".
Later life
In 1988, the Caltech Alumni Association bestowed an honorary membership on Ohshima for his contributions to the Caltech community. In 1993/1994, he received a teaching award from Caltech's undergraduate student organization. Ohshima retired from Caltech in 1994, after 37 years as a staff member. On May 22, 1994, around one hundred Caltech alumni assembled in the institution's gymnasium to honour Ohshima on the occasion of his retirement. In 2000, SKA opened "Shotokan Ohshima Dojo" in Santa Barbara, California, where Ohshima had moved his residence to. He led the SKA until his retirement in August 2018 at the age of 88. Apart from being the SKA's Shihan, he holds a similar position in Canada Shotokan Karate and other affiliated organizations. Ohshima is an advisory board member of Waseda Tomonkai Karate Club.
