Karasumaru Mitsuhiro was a notable court noble and poet of the late 16th and early 17th centuries.
During the battle of Sekigahara, he was sent as an official imperial envoy by Emperor Go-Yôzei to Tanabe castle to order Hosokawa Fujitaka (who was holding the castle at that time, and was under siege) to surrender. According to some accounts, he and his forces "rescued" Hosokawa and his men.
Karasumaru was chosen for this task in part because he had a personal relationship with Fujitaka. Over the course of four to five years, from 1598 to 1602, he met with Fujitaka more than 70 times, and compiled a collection of Fujitaka's thoughts on poetry, eventually publishing the volume under the title Jiteiki.
- Ono Masako, Tomita Chinatsu, Kanna Keiko, Taguchi Megumi, "Shiryô shôkai Kishi Akimasa bunko Satsuyû kikô," Shiryôhenshûshitsu kiyô 31 (2006), 251.