In 1903, seventeen-year-old Masuo Yasui left Nanukaichi in the Okayama prefecture of Japan for the western United States, stopping in Portland before he joined family members in working on the Union Pacific Railroad, along with thousands of other laborers from Japan. Two years later, Masuo returned to Japantown in Portland, Oregon, intent on learning English while working various jobs. Masuo later convinced his brother Renichi Fujimoto to move with him to Hood River, Oregon, which had a growing population of Japanese immigrant laborers. In 1908, Masuo Yasui and Renichi Fujimoto opened the Yasui Bros. Co. store in Hood River, the first iteration of what would become four locations of their successful business over the next three and a half decades.

A few years later, Masuo Yasui married Shidzuyo Miyake, a college-educated teacher also from Nanukaichi, Okayama, who joined him in Oregon in late 1912. Over the next two decades, the couple had nine children: sons Kay, sometimes spelled Kei (born 1914), Tsuyoshi, later known as Ray or Chop (born 1915), and Minoru, often known as Min (born 1917); daughters Yuki (born 1918) and Michi (born 1920); sons Roku (born 1922), Shu (born 1923), and Homer (born 1924); and youngest daughter Yuka (born 1927). Yuki died of an illness at age 3, and eldest son Kay committed suicide at age 17. Renichi Fujimoto married Matsuyo Senno in 1904, but obligations to Renichi's adoptive family in Japan, the Fujimotos, kept her from immigrating to the United States to join him until 1931. Renichi and Matsuyo had no children of their own, but were close with Masuo and Shidzuyo's children.

The Yasui Bros. Co. store played a central role as a social hub and meeting place for the Japanese American community in Hood River. Masuo became a vital contact for Japanese immigrants and their families. He frequently helped fellow Japanese Americans find employment and housing, and used his English fluency to assist with legal and government forms, such as citizenship documentation for children born in the United States, and to broker small land purchases. The Yasui Bros. store also sold life insurance and brokered steamship travel arrangements to and from Japan.

In addition to operating the store, the Yasuis took advantage of the agricultural potential in the Hood River Valley and surrounding areas, where they bought and leased land for their own farms and orchards in Dee, Mosier, and Willow Flat. Like many in the area, they produced apples and pears, but also strawberries and asparagus, which the Yasuis and other Japanese American farmers introduced to the region. Their farming operations spawned trucking and shipping businesses, and Masuo Yasui created a cooperative called the Mid-Columbia Vegetable Growers Association to help with packing and shipping of asparagus.

Masuo Yasui also served as a liaison between the Japanese American and white communities in Hood River, fielding inquiries from business owners in search of laborers and helping to settle disputes. Over time, Masuo grew into a leading representative of his community, founding the Japanese Savings Association of Hood River and constructing and operating a Japanese Community Hall, while also being a rare Japanese American member in mostly white organizations like the Rotary Club. He was the first Japanese American person elected to the powerful Apple Growers Association and received the most votes of any candidate in 1939. Throughout the 1920s and 1930s, Masuo Yasui was recognized by the Portland Japanese Consulate for his services to his community, and received awards from the Japanese government and other agencies for fostering business relations between the United States and Japan.

However, as the Yasuis and other Japanese immigrants prospered, anti-Japanese sentiment was growing among white residents in Hood River. In 1923, Oregon passed a bill preventing Japanese and Chinese immigrants from owning land, and a local Anti-Asiatic Association formed soon after. Anti-Japanese sentiment came to a boiling point after Japan's attack on Pearl Harbor on December 7, 1941. The FBI arrested Masuo Yasui, then 55, five days later with no official charges or evidence of treason. He would remain in government detention until after the end of the war, and was repeatedly transferred among various federal detention centers, including Fort Missoula, Montana; Fort Sill, Oklahoma; and Camp Livingston, Louisiana.

In February 1942, President Franklin D. Roosevelt signed Executive Order 9066, authorizing exclusion of "any and all persons" from areas designated by the military, which would, within months, result in the government's forced removal and mass incarceration of more than 120,000 Japanese Americans on the West Coast. In March, after being refused for U.S. military enlistment, Minoru Yasui, who had become a lawyer and was living in Portland, Oregon, deliberately violated a curfew imposed on Japanese Americans in order to be arrested and establish the basis for a legal challenge to the curfew. He was convicted and spent nine months in solitary confinement; during this time, his case reached the U.S. Supreme Court, but the court upheld his conviction and ruled that the curfew was legal.

The Yasui family's situation would continue to worsen; in the spring of 1942, the Yasui Bros. Co. store was forcibly closed and the family's other assets were frozen or confiscated. Not long afteward, Yasui family members were among the Japanese Americans sent by the U.S. government to incarceration camps, euphemistically called "war relocation centers," which were typically located in dry and desolate locations. While Masuo was held in Louisiana and Min was in solitary confinement in the Multnomah County Jail, Shidzuyo, Renichi, Matsuyo, Ray (also known as Chop or Tsuyoshi) and his wife, Mickie, as well as young Homer and Yuka, were sent first to the temporary Pinedale Assembly Center near Fresno, California, then to the Tule Lake incarceration camp. Min appealed unsuccessfully to the government for his father to join the rest of the family as Shidzuyo and other family members and friends wrote letters pleading for a rehearing, but all requests were denied. In June 1943, Masuo was transferred to the Santa Fe Detention Center in New Mexico, where his family could finally request to visit him. By this time, Minoru Yasui and Renichi and Matsuyo Fujimoto were being held at the Minidoka War Relocation Center in southern Idaho. Roku, Michi, and Shu Yasui, college students at the time, had avoided incarceration through geographical location or preemptive travel to Denver, Colorado.

Life in the camps was difficult for most of those incarcerated; families were largely separated, food was bad and extreme elements pierced the shoddily constructed barracks. The Yasuis wrote letters to each other through this period and visited Masuo as often as possible. Ray secured a work leave to do farm labor in Idaho, while Shidzuyo successfully petitioned for educational releases for her younger children; they joined Michi in Denver, where Minoru also came after his release in fall 1944. Despite an active letter-writing campaign with the support of senators and the Japanese American Citizens League, Masuo was detained until January 1946, five months after Japan surrendered and the war was declared to have ended. He joined the rest of the family in Denver upon his release.

As was the case for many other Japanese Americans, incarceration caused the Yasuis to lose their home, savings, businesses, and all but one of their farms, and they never regained what they once had. Hood River made national headlines toward the end of the war for its virulent racism and antagonism toward Japanese American residents to deter them from returning to the area, and the local post of the American Legion had waged a campaign against Masuo's release. Masuo and Shidzuyo left Denver to return to Oregon but resettled in Portland instead; only Ray Yasui returned to Hood River, to restore the now disheveled orchard in Willow Flat. In 1952, at their first opportunity to do so under federal law, the Issei (first generation) of Yasuis became United States citizens. Five years later, in declining health, Masuo died by suicide at the age of 70; Shidzuyo passed away of natural causes three years after his death. The second generation of Yasuis, the Nisei, built successful careers as lawyers, doctors, teachers, and entrepreneurs. Minoru Yasui's experiences during World War II led him to a lifelong career as a civil rights activist, for which he was posthumously awarded the Presidential Medal of Freedom in 2015. His siblings were also active in civil rights causes and served as strong advocates for redress in the 1980s, and led organizations including the Japanese American Citizens League, the Nikkei Legacy Center, and the Min Yasui Legacy Project.