was a Japanese mathematician. A world-renowned expert in functional equations, he is best known for discovering Haruki's theorem and Haruki's lemma in plane geometry.
Some of his published work, such as: "On a Characteristic Property of Confocal Conic Sections" is available (open source) on Project Euclid.
Haruki earned his MSc and PhD from Osaka University and taught there. He was a professor at the University of Waterloo in Canada from 1966 till his retirement in 1986. He was a founding member of the university's computer science department (1967).