Nukui Tsugumune served as a bushō during the Sengoku period. He was a retainer of the Noto-Hatakeyama clan. Tsugumune received one of the characters in his name from his lord, Hatakeyama Yoshitsugu.
The Nukui clan originated from Fujiwara no Toshihito, a noble and bushō from the early Heian period in the tenth century affiliated with the Uona branch of the Fujiwara-Hokke lineage. The Nukui were kokujin, or provincial landowners, in Noto.
In 1513, Tsugumune was born as the eldest son of Nukui Fusasada. Tsugumune supported his father in the overthrow of the Yusa clan and seized the authority of the Hatakeyama clan. In 1555, Fusasada was killed by his lord, Hatakeyama Yoshitsuna (the eldest son of Hatakeyama Yoshitsugu) after which Tsugumune fled with his son, Nukui Kagetaka, to Kaga Province.
Thereafter, Tsugumune formed a faction to oppose Yoshitsuna, comprised of Tsugumune’s uncles, Tsugumoto and Tsunasada, and the Noto-Miyake clan who had deep ties with the Nukui. The faction backed a member of the clan named Hatakeyama Harutoshi to launch a rebellion, but Tsugumune died in the ensuing battles, an event known as the Kōji Rebellion.