- "The bald rat will soon learn he can not simply take any life he pleases."
- ―Mogami Yoshiaki.[src]
In order to solidify his political position, Yoshiaki sent his daughter, Komahime, to be wed to Toyotomi Hidetsugu, nephew and heir to the Regent of Japan, Toyotomi Hideyoshi. However, soon after Hideyoshi had a son of his own, and in order to secure his succession, Hideyoshi ordered the death of his nephew and his family, including Komahime. This enraged Yoshiaki, who immediately turned his allegiance to Tokugawa Ieyasu.
- Yoshiaki was the uncle of Date Masamune.