Hokezu Sakinobu served as a bushō during the Sengoku and Azuchi-Momoyama periods. He was the lord of Hokezuhon Castle in Iyo Province. Sakinobu was counted as one of the Fifteen Generals of the Saionji. He was also known as Akinobu or Yahachirō.
The original name of the Hokezu clan was Kiyohara so they were called either the Hokezudono-Kiyohara clan or the Seike clan.
Initially, Sakinobu served the Saionji clan, and made many contributions on the battlefield during invasions by the Ōtomo (based in Bungo Province in northeast Kyūshū) and Chōsokabe (based in Tosa Province) clans. During invasions by the Ōtomo in 1560 and in 1570, Sakinobu fought valorously as a commander of naval forces.
In 1574, Ichijō Kanesada, the governor of Tosa Province, was ousted by the Chōsokabe clan and fled to Usuki in Bungo Province. In 1575, Kanesada sailed from Bungo in Kyūshū to Iyo in Shikoku, whereupon he made plans to regain his position in Tosa. On this occasion, Sakinobu, along with his lord, Saionji Kinhiro and the Shimazu clan of Satsuma Province, supported Kanesada.
In 1579, when Hisatake Chikanobu, a retainer of the Chōsokabe, invaded, Sakinobu cooperated with Doi Kiyoyoshi of Mima to defeat Chikanobu. In 1584, when the Chōsokabe army invaded, Sakinobu betrayed the Saionji in favor of the Chōsokabe in an effort to protect himself.
In 1585, however, during the Invasion of Shikoku by Hashiba Hideyoshi, the Chōsokabe withdrew from Iyo while the Kōno and Saionji clans surrendered to the invading forces. Sakinobu was permitted by Kobayakawa Takakage to reside in Hokezuhon Castle and participated under the command of Takakage in the Pacification of Kyūshū. In 1588, he was subsequently ordered by Toda Katsutaka (who moved to the Uwa District of Iyo) to come down from the castle and the Hokezu clan fell into ruin. Sakinobu was said to have gone to Kyūshū.