Inoo Tsuratatsu served as a bushō during the Sengoku period.  He was a retainer of the Imagawa clan and the lord of Hikuma Castle in the Fuchi District of Tōtōmi Province.

The Inoo clan were originally a lineage serving as members of the bugyōshū, or judicial magistrates, of the Muromachi bakufu.  In the early Sengoku period, the family headed toward Tōtōmi upon invitation of the Imagawa clan, the military governor of Suruga Province.  First, they served as magistrates in the Hamamatsu manor in territory held by the prominent Kira clan.  In the sixteenth century, after the Imagawa clan acquired control of Tōtōmi, the family continued governing the Hamamatsu manor and resided in Hikuma Castle.

By the middle of the sixteenth century, Tsuratatsu, as the successor to Inoo Noritsura, inherited the role as the lord of Hikuma Castle and landlord of Hamamatsu.  Around the time that Tsuratatsu became the lord of the castle, in the fifth month of 1560, Imagawa Yoshimoto, a sengoku daimyō and the eleventh head of the Imagawa clan, was killed by the Oda army at the Battle of Okehazama.  In neighboring Mikawa Province, the Matsudaira clan defected from the Imagawa and allied with the Oda clan.  In 1563, kunishū, or provincial landowners, in Tōtōmi including the Horigoshi, the Amano, the Matsui, and the Ii clans who had been serving the Imagawa joined a large-scale rebellion against the Imagawa.

That same year, Tsuratatsu also rebelled against the Imagawa.  Although he colluded with the Matsudaira of Mikawa, when Imagawa Ujizane deployed to Mikawa, Tsuratatsu feigned illness and returned to his home province of Tōtōmi.  It is also said that he did so after setting fire to the Shirasuka lodge.  In the twelfth month, the Imagawa attacked Tsuratatsu at Hikuma Castle.  Scores of defenders were killed in battle, but after the death of Niino Chikanori, the commander of the Imagawa forces, the siege ended in failure for the Imagawa.  After the battle, Tsuratatsu settled and returned to the service of the Imagawa, but, in 1564, he met Matsudaira Ieyasu of Mikawa and obtained reinforcements so the Imagawa deployed against to assault Hikuma Castle.  In the tenth month, Ujizane pardoned Tsuratatsu and ordered the destruction of Zudaji Castle where Tsuratatsu had holed-up.

In the twelfth month of 1565, Tsuratatsu served in Sunpu upon invitation of a member of the Matsui clan (the husband of his elder sister) upon orders of Imagawa Ujizane.  At this time, his residence was raided by Imagawa forces and he was executed.  In 1566, Ujizane suppressed a large-scale rebellion by kunishū, or provincial landowners, in Tōtōmi against the Suruga-Imagawa clan known as the Enshū Discord.  Nevertheless, he could not dispel his suspicions towards Tsuratatsu.  For a period of time, the affiliation of Hikuma Castle was uncertain but was finally pacified by the Matsudaira (Tokugawa) clan.

Excerpts from historical accounts of the Ii family

In an account of the Ii family serving as the lord of Iinoya Castle in the Inasa District of Tōtōmi compiled in the mid-Edo period, the Ii were the lords of Hikuma Castle and the Inoo clan served as chief retainers.  The Ii clan were blamed for the outbreak of a fire at the Shirasuka lodge (the thirty-second station along the Tōkaidō – a major route from Edo to Kyōto with fifty-three lodges) when Imagawa Ujizane was on deployment to Mikawa.  As a result, the Ii were ordered to attack the Amano clan who rebelled against the Imagawa, but Tsuratatsu’s wife was a relative of the Amano clan so he cut ties with the Ii clan.  During the deployment, he murdered Ii Naohira by serving poison-laced tea, forcibly took over Hikuma Castle, and rebelled against the Imagawa.  Upon invite of the Matsui clan, Tsuratatsu appears to have entered Sunpu but this was for the ostensible purpose of having his son wed Ujizane’s daughter and in the end Tsturatatsu and his son were forced to commit seppuku.

Descendants

His eldest son was Inoo Yoshihiro.  The custom of flying kites at the Hamamatsu Festival presumably began to celebrate the birth of Yoshihiro.  This is based on a historical account of Hamamatsu Castle stating that Sahashi Jingorō, a resident of the village of Irino, flew a large kite with Yoshihiro’s name on it to celebrate the birth of Yoshihiro as the eldest son of Inoo Buzen-no-kami (Tsuratatsu), the lord of Hikuma Castle during the Eiroku era (1555 to 1569) in the Sengoku period.  Recent research, however, suggests this story was a fabrication of the Tenshō era.

The Inoo were a family of noble heritage from the village of Onden in Edo calling themselves descendants of the second son of Inoo Tsuratatsu.  Inoo Yatayū, the second son of Inoo Buzen-no-kami Masazumi (Tsuratatsu, the last lord of Hamamatsu-Hikuma Castle who moved to this area during the Tenshō era) settled here.  Owing to their lineage from the Minamoto clan, the Inoo from this area adopted surname of Genjiyama and informed Tokugawa Iemitsu, the third shōgun of the Edo bakufu.