Homer Yasui, the eighth child of Masuo and Shidzuyo Yasui, was born in Hood River, Oregon, in 1924. He lived in Hood River with his family until 1942, when the Yasui family were among more than 120,000 Japanese Americans who were incarcerated by the U.S. government during World War II. Along with other family members and friends and neighbors from Hood River, Homer Yasui, then a teenager, was sent to the Pinedale Assembly Center and then the Tule Lake Relocation Center in California.

After advocacy by his mother, he was granted educational leave in the fall of 1942 to attend college in Denver, Colorado. He later attended medical school in Philadelphia, Pennsylvania. In 1950, Homer Yasui married Miyuki Yabe (1926-2018), later known as Miki. He joined the Navy Medical Corps as a surgeon in 1954 and opened a long-running practice in the Portland, Oregon, area in 1958. The couple had three children: Barbara, Meredith (Meris) and John.

Homer Yasui joined the Portland chapter of the Japanese American Citizens League (JACL) in 1969. He served as its president in 1973 and as co-president with his wife, Miki Yasui, from 1980-1981. Both served as JACL board members throughout the 1970s and 1980s, and Homer Yasui was elected governor for the Pacific Northwest District Council of the organization in 1982. He also served as co-chair of the Portland JACL Committee for Redress, along with local attorney Peggy Nagae.

In the late 1980s, as Homer Yasui was retiring from medicine, he became the Yasui family's unofficial historian. Over the next 30 years, he performed extensive research on his own family and other Oregon-based Japanese American families, gathered additional documents through his network and Freedom of Information Act requests, and wrote about their lives before and after their wartime incarceration by the U.S. government. He also wrote a series of informal biographies and family histories titled "Passing it On," which he sent to family and friends. Homer Yasui died in 2023.