Born in 1499 in Ogurayama Castle, Myōkyū was the daughter of Kikkawa Kunitsune, a lord in Aki Province.
Reaching adulthood, Myōkyū was married out of convenience to Mōri Motonari, a prominent warlord of Aki Province from the Mōri clan. With Motonari, she had a daughter (hostage of Takahashi clan; premature death caused by Takahashi following their downfall), Takamoto in 1523, Lady Goryū in 1529, Motoharu in 1530, and Takakage in 1533.
January 2, 1546, Myōkyū died in Koriyama Castle. She was 47. Her Dharma name is Myōkyūshiten Seishitsu Kyūkōtashi. Her grave's location is unknown.
Note
Although it was a political marriage, it is said that the relationship between Motonari and Myōkyū was good. For as long as Myōkyū was alive, Motonari took up no concubines.
Though her real name is unknown, it is speculated to be Tama (玉) or Hisa (久).