Jukei-ni (寿桂尼, c.1490 - 11 April 1568) was a Japanese noble lady who acted as the power behind the throne or de facto daimyo of the Imagawa clan during the Sengoku period.

[5][6] The three became samurai warlords, and their daughter Zukei-ni entered into a diplomatic marriage with Hojo Ujiyasu, an initial step towards the formation of the Kōsōsun Triple Alliance.

This alliance placed the daughters of the Imagawa clan, Takeda and Hojo in a political marriage, strengthening the ties between them, but it gave rise to the beginning of many diplomatic wars in neighboring regions.

Jukei-ni helped form the laws in the Imagawa clan's domain, acting actively as a political advisor during her husband's administration.

Jukei-ni's grandson, Imagawa Ujizane, is known for marrying Hojo Ujiyasu's daughter, Lady Hayakawa, thus initiating the triple alliance.

For having passed four generations of Daimyos, Jukei-ni had great political power in Suruga, Totomi, and Mikawa provinces and was known as "Female Daimyō" of Imagawa clan.