Yamashita began judo in primary school after being inspired by judo founder Kanō Jigorō, and had already attained a black belt by the time he reached junior-high school. Yamashita continued judo under the guidance of 1964 Summer Olympics gold medalist Isao Inokuma and 1967 World Judo Championships gold medalist Nobuyuki Sato after graduating from Tokaidai Sagami High School. His streak of 203 victories began in October, 1977, in an exhibition match held in the Soviet Union, and ended with his final match in April, 1985, where he won the All-Japan judo championships for the 9th consecutive time.