When Kay Kazuo Endow was born on 16 October 1930, in Douglas, Converse, Wyoming, United States, his father, John Seiki Endow, was 29 and his mother, Florence Miyoshi Ohta, was 21. He married Edna Loy Yau Tam on 14 September 1957, in Los Angeles, Los Angeles, California, United States. He lived in Election District 11, Fremont, Wyoming, United States in 1940. He died on 6 October 2005, at the age of 74.