Kiyosi Itô, Japanese mathematician and academic (died 2008)

Kiyosi Itô was a Japanese mathematician who made fundamental contributions to probability theory, in particular, the theory of stochastic processes. He invented the concept of stochastic integral and stochastic differential equation, and is known as the founder of so-called Itô calculus. He also pioneered the connections between stochastic calculus and differential geometry, known as stochastic differential geometry. He was invited for the International Congress of Mathematicians in Stockholm in 1962. So much were Itô's results useful to financial mathematics that he was sometimes called "the most famous Japanese in Wall Street".