Lifespan: Eishō (15xx) to Tenshō (15xx)
Lord: Mogami clan
Father: Shimizu Yoshitaka
Children: Shimizu-hime (wife of Mogami Yoshiaki)
Adopted Children: Mogami Yoshichika
Shimizu Yoshiuji served as a bushō during the Sengoku period. Yoshiuji was the sixth head of the Dewa-Shimizu clan.
Yoshiuji was born as the son of Shimizu Yoshitaka, the fifth head of the Shimizu and lord of Shimizu Castle in the Mogami District of Dewa.
The Dewa-Shimizu were an illegitimate branch of the Mogami and offshoot of the Narusawa family. The family began in 1476 when Narusawa Mitsuhisa, the son of Narusawa Kaneyoshi (the great-grandchild of Shiba Iekane), built Shimizu Castle at a strategic location along the Mogami River. He fought frequently against the neighboring Daihōji clan.
In 1565, Yoshiuji’s father, Yoshitaka, was killed in the course of a defeat against Daihōji Yoshimasu at the Battle of Motoaikai. Yoshiuji then succeeded his father. Yoshiuji built ties with the family of his lord, Mogami Yoshiaki and made progress in his conflicts against the Daihōji. He did not have a son so his daughter, Shimizu-hime, would have been expected to wed an individual who would become the successor but, instead, Yoshiaki’s third son, Mogami Yoshichika, was adopted and became Yoshiuji’s successor. After the death of Yoshiuji, Shimizu-hime, at the age of twenty, wed Yoshiaki whose formal wife from the Ōsaki clan had died.