Lifespan: Kyōroku 4 (1531) (?) to 4/26 of Keichō 18 (1613)
Clan: Tachihara (a branch of the Inuma clan descended from the Seiwa-Genji)
Lord: Amago Haruhisa → Amago Yoshihisa → Amago Katsuhisa
Father: Tachihara Yukitsuna (or Fukuya Kaneo)
Siblings: Yukitaka, Hisatsuna, Nami (wife of Yamanaka Mitsuyuki)
Wife: [Formal] Daughter of Fukuya Takakane (or younger sister of Katō Tsunemori)
Children: Mitsutada, daughter (wife of Satomura Takakane)
Adopted Children: Satomura Takakane (?)
Tachihara Hisatsuna served as a bushō from the Sengoku to early Edo periods. He was a retainer of the Amago clan. Together with Yamanaka Yukimori and Kumagai Shinemon, Hisatsuna was one of the Three Elites of the Amago – senior retainers of the clan recognized for their exemplary military prowess and loyalty to the clan. Hisatsuna was an uncle of Yukimori and served as the military adviser to his lord, Amago Yoshihisa, during the conflict with Mōri Motonari.
The Tachihara clan were direct retainers of the Amago and Hisatsuna appears as a magistrate on jointly signed documents issued by Amago Haruhisa, the predecessor of Yoshihisa as the head of the Amago clan.
Around 1531, Hisatsuna was born as the son of Tachihara Yukitsuna. In response to an assault by the Mōri army against Shiraga Castle, on 9/23 of Eiroku 6 (1563), Yoshihisa assigned his younger brother, Amago Tomohisa, to serve as the commander-in-chief of a contingent including Kamei Hidetsuna and over 10,000 troops and dispatched them to serve as a rear guard at Shiraga Castle. As the head of the attendants serving Yoshihisa, Hisatsuna advocated for them to serve as active reinforcements, but was overridden by high-ranking elders so his proposal was not adopted. The troops sent as a rear guard departed their camp at Makatahara, traversed the Ōhashi River and approached Wakura, but were repelled. In the course of withdrawing, Hisatsuna and Yamanaka Yukimori served in the rear guard, imposing significant casualties on the Mōri troops pursuing the retreating Amago forces, enabling Tomohisa to safely return to Toda.
In 1565, during the siege of Gassantoda Castle, Hisatsuna served under the command of Amago Tomohisa, joining Yukimori and Akiage Munenobu to guard the Shiotani entrance. In 1566, when Gassantoda Castle fell, Hisatsuna served as a messenger to negotiate the surrender. Owing to his outstanding efforts, the Mōri offered Hisatsuna to serve on their behalf for 2,000 kan, but he declined and went to live quietly in the capital of Kyōto.
Later, together with Yukimori and Jinzai Motomichi, Hisatsuna backed Amago Katsuhisa and endeavored to revive the Amago clan. In the ninth month of Eiroku 12 (1569), at the Battle of Mihonoseki, when the Amago revival army faced precarious circumstances in clashes with the opposing army led by Oki Tamekiyo, Hisatsuna gave encouragement to Yukimori who considered taking his own life, and reinvigorated the Amago forces. After going to Kyōto to solicit support from Oda Nobunaga, Hisatsuna was regarded as a good man of respectful nature and presented with a long sword made by Sadamune. The ties between the Amago clan and Oda Nobunaga were, in particular, attributable to the contributions of Hisatsuna. The Amago revival army was folded in to the army of Toyotomi Hideyoshi to conquer the Chūgoku Region.
In 1577, Kōzuki Castle was recovered from the Mōri and served as a base for Hisatsuna and the Amago revival army. In 1578, Hideyoshi was ordered to send some of his forces to participate in the Battle of Miki against Bessho Nagaharu who had separated from the Oda after becoming dissatisfied with the policies of Hideyoshi serving under the command of Nobunaga. To exploit the situation, the Mōri marched with 30,000 soldiers toward Kōzuki Castle. While the Battle of Miki continued, Hideyoshi attempted to send reinforcements to Kōzuki, but Nobunaga gave orders to send reinforcements to the Battle of Miki instead. Despite repeated appeals from Hideyoshi, Nobunaga refused to order the dispatch of reinforcements to the Amago revival army. After the Mōri army severed the supply lines, Kōzuki Castle fell and Amago Katsuhisa and Yukimori died, bringing to an end the pursuit to revive the Amago clan. Hisatsuna himself became a prisoner of the Mōri army, but, owing to illness, the rendering of a punishment was deferred, during which time he escaped. Hisatsuna went to the capital of Kyōto and relied for assistance upon his son-in-law, Fukuya Takakane, who served the Hachisuka family. He then resided in Inotsu in Awa Province in Shikoku.
Hisatsuna died on 4/26 of Keichō 18 (1613) at the age of eighty-three.
A historical record of retainers of the Hachisuka family contains the lineage and rank of each retainer of the Tokushima domain. Based on this account, the father of Fukuya Takakane was Tachihara Genta Hei-no-jō Hisatsuna, identifying him as the natural son of Hisatsuna. This differs from accounts of the Amago clan which depict Takakane as a son-in-law or Hisatsuna as a father-in-law. Also, with respect to his origins, Hisatsuna is identified as the son of Fukuya Kunai-Shōyū Kaneo such that his surname was Fukuya but he received the surname of Tachihara from Amago Yoshihisa and thereafter was called Tachihara Hisatsuna.
His descendants included Tsunematsu Seiji, a governor of Shimane Prefecture in the 1970’s and 80’s.