Born in Hood River, Oregon to Motokichi and Asa Matsui as the eldest of four children, Matsui was sent to be reared in Fukuoka, Japan, graduating from Oita Prefectural Commercial School in 1934. Returning to the states, he graduated from high school in Seattle and was in his last quarter at the University of Washington in March 1942 when he was inducted into the Army at Fort Lewis.

Throughout the war and in the immediate postwar period, Matsui served as a Japanese language instructor, and later as chairman, Academic Division, of the Military Intelligence Service Language School located at Camp Savage, then Fort Snelling, and finally at the Presidio of Monterey. He held the rank of warrant officer.

Ordered to Occupied Japan in August 1946, he was commissioned as a 2nd lieutenant, and was first assigned to the Economic & Scientific Section, GHQ, and then as commanding officer, 358th Interrogation Team, IX Army Corps in Hokkaido. Separated from active duty with the rank of 1st lieutenant at Camp Zama, Japan, in June 1947, he served as reserve 1st lieutenant, Military Intelligence, until discharged in January 1954.

Matsui remained in Japan after active duty service in the Judge Advocate Section, U.S. Eighth Army, Yokohama, as legal investigator, War Crimes Defense. His team was successful in gaining acquittal for Major General Uchiyama, Japanese Army Medical Corps, and obtaining light sentences for others. He took the opportunity to enroll at Senshu University in Tokyo, earning a BA in economics.

Returning to the University of Washington in 1950, Matsui completed his undergraduate studies, and a year later after receiving his BA in business administration, entered graduate school. He was with Barclay & Company of Seattle as assistant import manager for five years, and then served in various managerial positions, the last six years as deputy general manager, with Mitsubishi International Corporation, Seattle Branch. He was on loan to a subsidiary for a three year period in Everett, Washington, to introduce manufacturing technology of concrete poles and pilings. He retired from

Mitsubishi in 1987 after 30 years of service, and has since served as a Consultant in U.S.-Japan Trade.

Matsui is well known in greater Seattle and in the Northwest for his lifelong commitment to community services. He has participated in numerous service, business, cultural and veterans organizations in a variety of capacities, including serving as the founding president of the Military Intelligence Service, Northwest Association; commander of the Nisei Veterans Committee, Inc., Seattle; board member, Japan-America Society of the State of Washington; president, Japanese Community Service of Seattle; chairman, Seattle Cherry Blossom and Japanese Cultural Festival; Seattle Chamber of Commerce; past president, Seattle First Hill Lions Club; president, Taisho Kai; vice president, Seattle Buddhist Church; and president, Fukuoka Kenjin Club.

In 1953, Matsui had the signal honor of being selected as one of Seattle's 100 "Newsmakers of Tomorrow" by the Committee for Seattle's Future, in cooperation with Time magazine-the only Japanese American so honored. In

April 1994, Matsui was honored as the recipient of the 5th Order of the Rising Sun (Gold and Silver Rays), for a lifetime spent promoting better U.S. - Japan relations.