Mitsuo Kawaguchi, was born on October 7, 1924, in Huntington Beach, California to Yasu and Hirokichi Kawaguchi. He was immersed in the farming lifestyle at a young age along with his older brother, George, and sisters Tsuruyo and Teruko.

In 1933, the Long Beach earthquake completely destroyed his grammar school on what was fortunately a day off from school, sparing the students and faculty. They were able to continue their education by holding classes in private homes.

Just five years later, he also survived the Santa Ana River flood which flooded his family home and farm.  He often spoke of how they had to move their horses to higher ground.  Mitsuo attended Huntington Beach Union High School in the winter of 1940 until 1942. He was on the swim team and held numerous school records in the backstroke. Being a strong swimmer, he also excelled at water polo.

On December 7, 1941, the Empire of Japan attacked Pearl Harbor, and the United States entered World War II, disrupting the Kawaguchi family's way of life. The sentiment in their surrounding community shifted, with a lot of the American public uncertain and suspicious of anyone of Japanese descent. A few months later, President Franklin Roosevelt issued Executive Order 9066 on February 19, 1942, which called for the forceful incarceration of all Japanese Americans. Mitsuo and his family had just a few days to pack up what they could carry before they were incarcerated and sent to a U.S. concentration camp in the desert of Poston, Arizona. Mitsuo said this was the scariest time of his life as the temperatures rose to 130 degrees Fahrenheit, people were getting sick, and they were exposed to rattlesnakes and scorpions in the Arizona desert. Yasu, Satoshi, and Teruko would remain in the concentration camp until the end of the war in 1945, while after some time in Poston, George and Mitsuo were granted permission to work in Naperville, Illinois on a mushroom farm in order to earn a living for their family.

In 1945, Mitsuo was drafted into the U.S. Army and sent over after Germany surrendered. For 18 months, he served as a military police officer and was assigned to guarding the supply trains in occupied Germany. He and his brother George, who served in the famed 442nd Regimental Combat Team, returned home when their military services ended, rejoining their family in Fountain Valley.

The Kawaguchi family continued to farm after the war. They were more fortunate than many other interned Japanese American families because they were able to entrust their property and farm equipment to their local neighbors, the Courreges family, who protected it from attempted theft and vandalism fueled by anti-Japanese sentiment. In addition to the Courreges family's help, the Kawaguchi family's farm hand, Juan Miranda, stayed on during the war and tended to the land, keeping it in good condition until their return.

In 1952, Mitsuo met Jeanette Hiroko Niizawa at a dance. They enjoyed going to dances, movies, and spending time together. They married in October 1953 and settled in Huntington Beach. They had three children together, Gayle, Tom and Gary. In 1964, Mitsuo built a home for his family in Fountain Valley, California.

Mitsuo formed a partnership with his brother George called Kawaguchi Bros. and specialized in farming asparagus alongside a variety of crops such as chili, tomatoes, string bean, cauliflower, lettuce, and cabbage throughout Los Alamitos, Anaheim, Huntington Beach, and Fountain Valley. During the 1960s through the late 80s, Mitsuo and George farmed 80 total acres in Fountain Valley.

In 1989, Mitsuo and George officially retired from farming, but continued to be business partners for the rest of their lives until George's passing in 2010 at the age of 91.

After over 40 happy years of marriage together, Mitsuo's wife Jeanette passed away in July of 1995.

Throughout the years, Mitsuo enjoyed stamp and coin collecting, leatherwork, woodworking, film photography, and riding his 1947 Harley Davidson motorcycle. He traveled the world from Europe to Japan, and explored different parts of the United States. He enjoyed gardening and continued to grow a variety of fruits and vegetables in his backyard. He loved playing with his cats, Mia and Sora. In April of 1999, he married his second wife Michiko Kawauchi.

Mitsuo was a philanthropist and enjoyed participating in events for his favorite community organization, OCBC Project Kokoro, which was founded 40 years ago as a volunteer and non-profit outreach program to care for the health and well-being of the seniors in the Japanese American community. He was a proud supporter especially because his brother-in-law, Bill Wada, was a founding member. Many wonderful memories were made through Project Kokoro's many field trips, parties, and events.

In 2009, at 85 years old, he suffered a brain injury from a fall off a ladder. He worked towards a full recovery and even studied the DMV handbook to learn to drive again. After his heart bypass surgery in 2011, he took up walking on the treadmill, determined to strengthen his cardiac health. In 2015 at 91, he was diagnosed with kidney disease, but continued to enjoy life with the support of dialysis treatment three times a week. He never complained.

Mitsuo was a wonderful grandpa to his grandchildren, Douglas, Stacy, Kellyn, Cole, and Kyle, and enjoyed spending time with family throughout his life. In his later years, he was often surrounded by his family, and looked forward to weekly Sunday barbecues at his house.

Mitsuo Kawaguchi passed away peacefully on January 24, 2023, with family at his side. He lived to be 98 years of age. And he was very loved.