Japanese mathematician who received his Ph.D. from Kyoto University in 1978. In 1990 he joined the faculty of the Research Institute for Mathematical Sciences at Kyoto University. He was a recipient of the 1990 Fields Medal for his work in algebraic geometry. In 1979 he proved Hartshorne's conjecture, an unsolved problem in algebraic geometry. This work focused on developing new techniques for the classification of different algebraic varieties in dimension three.