[6] From an early age he was very interested in botany, though he also excelled at mathematics (teaching himself geometry and other maths during a lengthy convalescence due to food poisoning).

After entering a selective high school in Nagoya, Kimura focused on plant morphology and cytology; he worked in the laboratory of M. Kumazawa studying the chromosome structure of lilies.

With Kumazawa, he also discovered how to connect his interests in botany and mathematics: biometry[7] Due to World War II, Kimura left high school early to enter Kyoto Imperial University in 1944.

On the advice of the prominent geneticist Hitoshi Kihara, Kimura entered the botany program rather than cytology because the former, in the Faculty of Science rather than Agriculture, allowed him to avoid military duty.

He joined Kihara's laboratory after the war, where he studied the introduction of foreign chromosomes into plants and learned the foundations of population genetics.

After meeting visiting American geneticist Duncan McDonald (part of the Atomic Bomb Casualty Commission), Kimura arranged to enter graduate school at Iowa State College in the summer 1953 to study with J. L.

[7] Kimura soon found Iowa State College too restricting; he moved to the University of Wisconsin to work on stochastic models with James F. Crow and to join a strong intellectual community of like-minded geneticists, including Newton Morton and most significantly, Sewall Wright.

[7] As new experimental techniques and genetic knowledge became available, Kimura expanded the scope of the neutral theory and created mathematical methods for testing it against the available evidence.