He was from the second crop of foals sired by Epiphaneia who won the Kikuka Sho and the Japan Cup and was rated the second-best horse in the world in 2014. Efforia's dam Katies Heart showed some racing ability in Japan, winning three minor races on dirt from fifteen starts. She was a half-sister to the dam of Admire Moon and a grand-daughter of the Irish-bred mare Katies whose other descendants have included Sleepless Night (Sprinters Stakes) and Hishi Amazon (Hanshin Juvenile Fillies, Queen Elizabeth II Commemorative Cup).
