Roy Kodani was born in Hilo on the Big Island of Hawaii and attended Hilo High School. He graduated from Lafayette College in Easton, Pennsylvania and George Washington University Law School in Washington, D.C. While attending Law School, he worked in the office of United States Senator Oren E. Long of Hawaii and in the law firm of Meyers & Batzell, specializing in administrative law, in Washington, D.C. Upon returning to Hawaii and been admitted to the Hawaii Bar, he was appointed a Deputy Attorney General in the State of Hawaii and assigned to the Real Estate Commission and the Department of Taxation. He has been Examiner of Titles of the Land Court since 1973 and has been a licensed real estate broker in Hawaii over twenty-five years.

Roy Kodani was an Arbitrator of the State of Hawaii First Circuit Arbitration program. He has served as Secretary of the Board of Bar Examiners. He has been a frequent lecturer at professional and university seminars and classes on real estate and probate in Hawaii and on his experience in international law practice.

He is a Director of several Hawaii corporations or subsidiaries of foreign companies doing business in Hawaii. He is a member of the Hawaii State Bar Association, and the Japan America Society of Honolulu. He has devoted time to community organizations as an officer and director, among which are the Hawaii Diabetes Association, Neighborhood Board No.2 (Waialae Iki), Friends of the Library of Hawaii, and Children's Literature Hawaii. He is the attorney for other community organizations such as Friends of the Royal Hawaiian Band and 808 Racquetball Club.