A soldier from 1921-1922, Tusnamitsu Adachi entered the faculty of agriculture of the University of Tokyo in 1925. Here he became an assistant in 1932 then an associate professor in 1948. In 1954,he accepted the post of professor at Toyo University.He retired in 1976.
Adachi was the author 75 scientific papers, principally on entomology, most on Staphylinidae. He was the author of eleven new species all from Japan.