Hara Masatane served as a bushō during the Sengoku period.  Masatane was a retainer of the Kai-Takeda clan and one of the Twenty-Four Generals of the Takeda.

Masatane was born as the eldest son of Hara Masatoshi.  The Hara from which Masatoshi and Masatane originated were a branch of the Toki clan of Mino Province.  Hara Toratane, a commander of the ashigaru, or foot soldiers, in the Takeda family originated from a branch of the Chiba clan – a separate lineage from Masatoshi and Masatane.

In 1550, Masatane inherited the headship of the family and served as a director of a cavalry of 120 mounted soldiers as a senior figure in the Takeda clan.

Masatane’s name first appears on a document for deployment to the Shimoina District under the Koike clan of Kai for the invasion of Mino in the eleventh month of 1556.  As a close associate of Takeda Shingen, Masatane performed official duties including the issuance of licenses with seals under the provincial laws.  In 1561, during an invasion of the western portion of Kōzuke Province, Masatane joined Atobe Katsusuke, Sone Toranaga, and Tsuchiya Masatsugu as intermediaries with influential clans in Kōzuke.

Masatoshi served as an intermediary between the Ichinomiya-Nukisaki Shrine and the Takayama, Obata and Takada clans.  In a written pledge for Shimonogo from 1567, he was responsible for the pledge from the Kōzuke clans.

In the seventh month of 1569, during the Invasion of Suruga and after two earlier attempts, the Takeda finally captured Ōmiya Castle which had been held by the Fuji clan on the side of the Imagawa.  Masatane, along with Ichikawa Masafusa, governed shrines and temples including the Fuijsan-Hongū Sengen Grand Shrine and the Shizuoka Sengen Shrine.  Given that Masatane was active in the area around Ōmiya Castle, he may also have served as the chamberlain of the castle.  He further served as an intermediary between Asahina Nobuoki and Matsui Munetsune.

Masatane’s name appears along with Yamagata Masakage on licenses with seals to provide assorted exemptions from levies and for military conscription to the citizens of townships and villages in Kai Province.  His name further appears on verdicts and other documents related to the resolution of disputes.

Although the timing and details are unclear, he temporarily lost his position and, between 1570 and 1572, was pardoned through the mediation of Kankura Hyōgo-no-suke, a retainer of the Hōjō under the command of the Usui-Hara clan.  On 5/21 of Tenshō 3 (1575), Masatane was killed in action at the Battle of Nagashino against the allied forces of Oda Nobunaga and Tokugawa Ieyasu.