豊臣秀頼
The older sister of Takatsugu's wife, Yodo-dono, was the concubine of Toyotomi Hideyoshi and mother of Toyotomi Hideyori. Takatsugu's sister and Yodo-dono's cousin, Kyōgoku Tatsuko, was also became Hideyoshi's concubine. In marriage, Takatsugu became a brother-in-law of Hideyoshi.