Mas Oyama
, more commonly known as Mas Oyama, was a karate master who founded Kyokushin Karate, considered the first and most influential style of full contact karate. A Zainichi Korean, he spent most of his life living in Japan and acquired Japanese citizenship in 1968. Early life. Mas Oyama was born as Choi Young-Eui () in Kintei, Chōsen. At a young age he was sent to Manchukuo to live on his sister's farm. Oyama began studying Chinese martial arts at age 9 from a Chinese farmer who was working on the farm. His family name was Lee and Oyama  said he was his very first teacher. The story of the young Oyama's life is written in his earlier books. His family was of the landed-gentry class, and his father, Choi Seung Hyun, writing under the pen name of "Hakheon," was a noted composer of classical Chinese poetry. In March 1938, Oyama left for Japan following his brother who enrolled in the Imperial Japanese Army’s Yamanashi Aviation School. Sometime during his time in Japan, Choi Young-Eui chose his Japanese name, Oyama Masutatsu (), which is a transliteration of "Baedal" (). Baedal was an ancient Korean kingdom known in  Japan during Oyama's time as "Ancient Joseon". One story of Oyama's youth involves Lee giving young Oyama a seed which he was to plant; when it sprouted, he was to jump over it one hundred times every day. As the seed grew and became a plant, Oyama later said, "I was able to jump between walls back and forth easily." The writer, Ikki Kajiwara, and the publisher of the comics based the story on the life experience Oyama spoke to them about – thus the title became "Karate Baka Ichidai" (Karate Fanatic). In 1963, Oyama wrote "What is Karate  which became a best seller in the US and sold million copies all over the world. It is considered by many to be the Bible" of Karate to this day. It was translated into Hungarian, French, and English. Post-World War II. In 1945 after the war ended, Oyama left the aviation school. He finally found a place to live in Tokyo. This is where he met his future wife Oyama Chiyako (大山 置弥子) whose mother ran a dormitory for university students. In 1946, Oyama enrolled in Waseda University School of Education to study sports science. Wanting the best in  instruction, he contacted the Shotokan dojo (Karate school) operated by Gigō Funakoshi, the third son of karate master and Shotokan founder Gichin Funakoshi. He became a student, and began his lifelong career in Karate. Feeling like a foreigner in a strange land, he remained isolated and trained in solitude. Oyama later attended Takushoku University in Tokyo and was accepted as a student at the dojo of Gichin Funakoshi where he trained for two years. Oyama then studied Gōjū-ryū karate for several years with Nei-Chu So ( / 曺（曹）寧柱, 1908–1996) who was a fellow Korean from Oyama's native province and  a senior student of the system's founder, Chojun Miyagi. At sometime between 1946 and 1950, Mas Oyama trained at Kanbukan, a dojo founded by high ranking students of Kanken Toyama known for its large degree of Zainichi Korean membership. Nei-Chu So was also an active trainee at Kanbukan and likely taught Goju-Ryu to Oyama there. In Kanbukan, Karate was practised with Bōgu/protective gear (Bogutsuki Karate), which allowed for delivering strikes with full force, and may have influenced Oyama's full contact fighting mentality. However, sources say that Oyama had little interest in Bogutsuki Karate as a  sport. Around the time he also went around Tokyo getting in fights with the U.S. Military Police. He later reminisced those times in a television interview, "Itsumitemo Haran Banjyo" (Nihon Television), "I lost many friends during the war- the very morning of their departure as Kamikaze pilots, we had breakfast together and in the evening their seats were empty. After the war ended, I was angry- so I fought as many U.S. military as I could, until my portrait was all over the police station." Oyama retreated to a lone mountain for solace to train his mind and body. He  set out to spend three years on Mt. Minobu in Yamanashi Prefecture, Japan. Oyama built a shack on the side of the mountain. One of his students named Yashiro accompanied him, but after the rigors of this isolated training, with no modern conveniences, the student snuck away one night, and left Oyama alone. With only monthly visits from a friend in the town of Tateyama in Chiba Prefecture, the loneliness and harsh training became grueling. Oyama remained on the mountain for fourteen months, and returned to Tokyo a much stronger and fiercer karateka. Oyama greatly credited his reading of "The  Book of Five Rings" by Miyamoto Musashi (a famous Japanese swordsman) for changing his life completely. He recounts this book as being his only reading material during his mountain training years. He was forced to leave his mountain retreat after his sponsor had stopped supporting him. Months later, after he had won the Karate Section of Japanese National Martial Arts Championships, he was distraught that he had not reached his original goal to train in the mountains for three years, so he went into solitude again, this time on Mt. Kiyosumi in Chiba Prefecture, Japan and he trained there for  18 months. Founding Kyokushin. In 1953 Oyama opened his own karate dojo, named Oyama Dojo (form of Gōjū-ryū), in Tokyo but continued to travel around Japan and the world giving martial arts demonstrations, which included knocking live bulls unconscious with his bare hands (sometimes grabbing them by the horn, and snapping the horn off). His dojo was first located outside in an empty lot but eventually moved into a ballet school in 1956. The senior instructors under him were T. Nakamura, K. Mizushima, E. Yasuda, M. Ishibashi, and T. Minamimoto. Oyama's own curriculum soon developed a reputation as  a tough, intense, hard-hitting but practical style which was finally named Kyokushinkai (Japan Karate-Do Kyokushinkai), which means 'the ultimate truth,' in a ceremony in 1957. He also developed a reputation for being 'rough' with his students, as the training sessions were grueling and students injuring themselves in practice fighting (kumite) was quite common. Along with practice fighting that distinguished Oyama's teaching style from other karate schools, emphasis on breaking objects such as boards, tiles, or bricks to measure one's offensive ability became Kyokushin's trademark. Oyama believed in the practical application of karate and declared that  ignoring 'breaking practice is no more useful than a fruit tree that bears no fruit.' As the reputation of the dojo grew students were attracted to come to train there from inside and outside Japan and the number of students grew. Many of the eventual senior leaders of today's various Kyokushin based organisations began training in the style during this time. In 1964 Oyama moved the dojo into the building that would from then on serve as the Kyokushin home dojo and world headquarters. In connection with this he also formally founded the 'International Karate Organization Kyokushin kaikan' (commonly  abbreviated to IKO or IKOK) to organise the many schools that were by then teaching the kyokushin style. In 1961 at the All-Japan Student Open Karate Championship, one of Oyama's students, Tadashi Nakamura, at 19 years old (1961) made his first tournament appearance, where he was placed first. Nakamura later became Mas Oyama's Chief Instructor as referenced in Mas Oyama's book, "This is Karate." In 1969, Oyama staged the first All-Japan Full Contact Karate Open Championships which took Japan by storm and Terutomo Yamazaki became the first champion, which have been held every year since . In 1975, the first World Full Contact Karate Open Championships were held in Tokyo. World championships have been held at four-yearly intervals since. After formally establishing Kyokushin-kai, Oyama directed the organization through a period of expansion. Oyama and his staff of hand-picked instructors displayed great ability in marketing the style and gaining new members. Oyama would choose an instructor to open a dojo in another town or city in Japan, whereupon the instructor would move to that town, and, typically demonstrate his karate skills in public places, such as at the civic gymnasium, the local police gym  (where many judo students would practice), a local park, or conduct martial arts demonstrations at local festivals or school events. In this way, the instructor would soon gain a few students for his new dojo. After that, word of mouth would spread through the local area until the dojo had a dedicated core of students. Oyama also sent instructors to other countries such as the United States, Netherlands, England, Australia and Brazil to spread Kyokushin in the same way. Oyama also promoted Kyokushin by holding "The All-Japan Full Contact Karate Open Championships" every year and "World Full Contact Karate  Open Championships" once every four years in which anyone could enter from any style. Public demonstrations. Oyama devised the 100-man kumite which he went on to complete three times in a row over the course of three days. He was also known for fighting bulls bare-handed. He battled 52 bulls over the course of his lifetime, supposedly cutting off the horns of several and killing three instantly with one strike, earning him the nickname of "Godhand". Oyama is said to have had many matches with professional wrestlers during his travels through the United States. Later years. In 1946 , Oyama married a Japanese woman, Oyako Chiyako (1926-2006) and had three children with her. In the late 1960s, Oyama and Chiyako were having marital problems and decided to separate, and Chiyako, who did not want her husband to start seeing other women, arranged for a Korean woman and family friend named Sun-ho Hong to become Oyama's companion for some time. With Hong, Oyama had three more children and he would remain romantically involved with both Hong and Chiyako until the end of his life. Later in life, Oyama suffered from osteoarthritis. Despite his illness, he never gave  up training. He held demonstrations of his karate, which included breaking objects. Oyama wrote over 80 books in Japanese and some were translated into other languages. Final years and death. Oyama built his Tokyo-based International Karate Organization, Kyokushinkaikan, into one of the world's foremost martial arts associations, with branches in more than 100 countries boasting over 12 million registered members. In Japan, books were written by and about him, feature-length films splashed his colourful life across the big screen, and comic books recounted his many adventures. Oyama died at the age of 70 in Tokyo, Japan on  April 26, 1994, due to lung cancer. His widow Chiyako Oyama, made a trust foundation to honor his lifelong work.