According to "Kuya-rui," written by MINAMOTO no Tamenori, and "Nihon Ojo Gokuraku-ki," by YOSHISHIGE no Yasutane, there was a view that Kuya had descended from the Imperial Family (as an illegitimate child of the Emperor Daigo) during his life, but he did not voluntarily speak about his parents.
源為憲の『空也誄』や慶滋保胤の『日本往生極楽記』によれば、空也にはすでに生存中から皇室の出である（醍醐天皇の御落胤）という説があったが，みずからは父母のことを語ることはなかったという。