Tsutomu Ohshima

is a prominent Japanese master of Shotokan karate who founded the organization Shotokan Karate of America (SKA). He is the Shihan (Chief Instructor) of the SKA, and to this day holds the rank of 5th dan, which was awarded to him by Gichin Funakoshi.

Early life Ohshima was born on August 6, 1930, in Qingdao, China. His family moved back to Japan just before the outbreak of World War II. By the age of five, he had already begun learning martial arts.

Karate career Ohshima began studying karate in 1948, while a student at Waseda University.

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. 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. The arrangement did not work out satisfactorily, and was to be a source of bitterness between the two masters. In the end, unhappy with Nishiyama's actions and the direction being taken, Ohshima settled in the US and continued teaching there.

During the mid-1970s, Ohshima lived near Griffith Observatory in Los Angeles. He also demonstrated the nineteen Shotokan kata for Funakoshi's book. 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.

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. Ohshima officially retired as Shihan in August, 2018 when, at the age of 88, he appointed his successors in SKA and affiliated organizations.