The Ejima-Ikushima affair (江島生島事件 Ejima Ikushima jiken?) was the most significant scandal in the Ōoku, the shogun's harem, during the Edo period of the history of Japan.
On the twelfth day of the first month of the fourth year of the Shōtoku era (February 26, 1714 by the Western calendar), Ejima, a high-ranking lady in the Ōoku, visited the grave of the late shogun Tokugawa Ienobu as a proxy for her superior, Gekkō-in, who had been a lady-in-waiting to the late shogun and was the mother of the ruling shogun Tokugawa Ietsugu. Ejima then accepted an invitation to attend a kabuki performance by the popular actor Ikushima Shingorō at the Yamamura-za. After the performance, she invited the actor and others to a party at a tea house.
The party ran late and Ejima missed the closing of the gates to the Ōoku. As she went from one gate to the next trying to gain entry, word of her situation reached the officials within, and Ejima became the focus of a power struggle between her superior Gekkō-in, and Gekkō-in's rival Ten'ei-in, the wife of the late Ienobu. They in turn were part of a larger power struggle between two factions. One faction was led by Arai Hakuseki and Manabe Akifusa, the two closest advisors to both Ienobu and Ietsugu. The other was headed by fudai daimyo and the rōjū who had been in office since the time of the fifth shogun Tokugawa Tsunayoshi.