Lifespan: Tenbun 15 (1546) to 7/11 of Eiroku 12 (1569)
Other Names: Torafusamaru (childhood), Rokurō
Rank: bushō, sengoku daimyō
Title: Junior Fourth Rank (Lower), Master of the Eastern Capital Office
Father: Itō Yoshisuke
Siblings: Taki (wife of Kimotsuki Yoshikane, wife of Sugita Munemori), Asō (wife of Kitahara Kanemori, wife of Mangata Uemon-no-suke), 歓虎丸, Yoshimasu, 尼公方丈東興庵, 町上 (wife of Itō Sukeharu, mother of Itō Mancio), sister (wife of Itō Sukenobu), Shōgakuin, Suketake
Wife: [Formal] Akita (daughter of Ichijō Fusamoto); [Consort] Fukuzono (younger sister of Nomura Matsutsuna)
Children: Yoshikata, Sukekatsu, Otora-no-kata (formal wife of Itō Suketake)
Itō Yoshimasu served as a bushō and sengoku daimyō during the Sengoku period. He was the twelfth head of the Hyūga-Itō clan and the lord of Tonokōri Castle.
In 1546, Yoshimasu was born as the son of Itō Yoshisuke, a sengoku daimyō and the eleventh head of the Hyūga-Itō. Yoshimasu’s older brother, 歓虎丸, was an illegitimate son and died early so Yoshimasu became the designated successor to Yoshisuke. In 1560, he inherited the headship of the clan, became the lord of Tonokōri Castle, and, under the guardianship of Yoshisuke, oversaw the period of peak prosperity of the Itō family. Yoshimasu was known as being smart, brave and of a congenial nature so he was idolized more so than his father among the band of retainers and local citizens.. After becoming the head of the family, he remained in Tonokōri while Yoshisuke moved to Sadowara Castle, sharing duties of governance.
In 1569, while staying at the Iwasaki-Inari Shrine in Tonokōri for prayer, Yoshimasu fell ill and died. Afterwards, an unusual memorial service was held in which all of the persons in Tonokōri Castle underwent the rites of tonsure and prayed for his soul.
Yoshimasu’s formal wife, Akita, was the daughter of Ichijō Fusamoto. According to records of the Satsuma domain, Yoshimasu wed her through the offices of Itō Ōinosuke. The couple had three children including Itō Yoshikata, Itō Sukekatsu, and Otora-no-kata (formal wife of Itō Suketake).
In addition to his formal wife, there is an account in records of the Satsuma domain that Yoshimasu kept a consort even though she does not appear in genealogical records of the Itō clan. Fukuzono, the younger sister of Nomura Matsutsuna, was his consort before he was married. After marrying Akita, Yoshimasu sent Fukuzono back to the Nomura clan. Upon orders of Akita, however, she was murdered. Later, this act was a reason for the complicity of the Nomura in an event known as the Collapse of the Itō in 1577. Although Fukuzono does not appear in the genealogy of the Nomura clan in historical records of the Satsuma domain, it is noted that she was murdered upon orders of Yoshimasu’s wife.