He began his professional career in 1954 as a professor of Applied Physics at Waseda University in Tokyo.  He held this position until 1960 when he came to the United States on an exchange program with Duke University.  At Duke, he taught polymer rheology. In the early 1960s Tokita joined the U. S. Rubber Company in New Jersey, later Uniroyal, working there for 30 years on elastomer processing. He later joined Uniroyal Goodrich Tire Company in Akron in a research role.  He joined Cabot Corporation in Billerica in 1990. During his career he produced 9 U.S. Patents.  His most cited scientific article treated the subject of morphology formation in elastomer blends.