Career
Cox met Yoko Ono in 1961, after he saw some of her art work in an anthology and located her in Tokyo. The couple married on November 28, 1962. The marriage was annulled on March 1, 1963 due to Ono neglecting to officially finalize her divorce from first husband the Japanese composer Toshi Ichiyanagi, but they remarried on June 6 of that year.
Their daughter, Kyoko Chan Cox, was born August 8, 1963.
Cox became a full-time caregiver for Kyoko, while both he and Ono continued with their art, collaborating as conceptual artists. After a legal battle, Ono was awarded permanent custody of Kyoko.
He left The Walk after a few years, and in 1978, Cox and Kyoko stayed with the Jesus People United States of America commune in Chicago. He and Kyoko contacted Yoko Ono after the death of Lennon in 1980, but did not specify their location and afterward, Ono agreed to no longer attempt to locate Kyoko, but still wished to make contact with her.
Kyoko eventually made contact with Ono in 1994 and they are in close contact to this day.