Masutatsu Oyama (大山 倍達 Ōyama Masutatsu?, born Choi Yeong-eui (Hangul: 최영의 Hanja: 崔永宜); July 27th, 1923 – April 26, 1994), 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.[2][3] A Zainichi Korean, he spent most of his life living in Japan and acquired Japanese citizenship in 1964. He was an alumnus of Waseda University.[4]