Motoo Kimura was born on 13 November 1924 in Okazaki City, Aichi Prefecture, Japan. After graduating from high school in Nagoya, he entered the Faculty of Science, Kyoto University. He studied botany under the guidance of Professor Hitoshi Kihara at the Faculty of Agriculture of Kyoto University, but also taught himself population genetics theory. After graduating in 1947, he became a research assistant in Kihara’s laboratory. He was appointed as a staff scientist at the National Institute of Genetics when it was established in 1949 and became Head of the newly created Division of Population Genetics in 1964. He worked there until he passed away on 13 November 1994. In 1953 he studied at Iowa State University and in 1955 at the University of Wisconsin, where he received a PhD under the guidance of Professor James. F. Crow. Motoo Kimura received many honors, including the Order of Culture from the Japanese Government in 1976 and the Darwin Medal in 1992.