The eldest son of Nanjo Munekatsu, lord of Hagiishi Castle. He inherited headship in 1575 and initially served the Mori, but broke away in 1579 to join the Oda side. On April 24, 1580, with his brother Motokiyo, he attacked Yabase Castle in two waves in an attempt to seize it, but was repelled by its Mori-allied defenders. Though he lost his base at Hagiishi Castle to a Mori assault in 1582, he recovered eastern Hoki in 1584 after the peace between Hideyoshi and the Mori. He fought at the 1590 Siege of Odawara despite poor health and died the following year at age 43.

A local lord who defected from the Mori to the Oda side and, even after losing his base, persistently worked to recover his territory. In his later years he served Hideyoshi loyally despite failing health.

Though his attack on Yabase Castle failed, it stands as a concrete record of the contest between Mori and Oda forces across eastern Hoki.