- Other Names: Okiya-no-kata, Teruko, Sakyô-no-tsubone
- Japanese: 月光院 (Gekkou-in)
She was the third of Ienobu's concubines to give him a son, after Okomu no kata and Osume no kata. However, these two previous boys died at the ages of two months and two years, respectively. Gekkô-in's son Nabematsu survived to be named shogun at the age of three, upon Ienobu's death in 1712.
- Arai Hakuseki, Joyce Ackroyd (trans.), Told Round a Brushwood Fire, University of Tokyo Press (1979), 315n94.
- Cecilia Segawa Seigle, “Tokugawa Tsunayoshi and the Formation of Edo Castle Rituals of Giving,” in Martha Chaiklin (ed.), Mediated by Gifts: Politics and Society in Japan 1350-1850, Brill (2017), 126, 136.