Takenomata Masatsuna served as a bushō in Echigo Province during the Sengoku period.
The Takenomata clan was an illegitimate branch of the Kaji clan and a member of the Sasaki clan of the Agakita Group.
Masatsuna was born as the second son of Takenomata Kiyotsuna.
In the sixth month of 1503, Jōjō Sadazane received the daughter of Uesugi Fusayoshi, the military governor of Echigo, as his formal wife and became Fusayoshi’s son-in-law, changing his name to Uesugi Sadazane. In the eighth month of 1507, Nagao Tamekage, the deputy military governor of Echigo, gave support to Sadazane to oust Fusayoshi. On 11/6 of 1508, Sadazane became the military governor but, in fact, was a puppet of Tamekage. Around this time, Sadazane wed the younger sister of Tamekage. His formal wife, Fusayoshi’s daughter, is believed to have died as of this time.
Gradually, however, Sadazane came to resent serving as a puppet for Tamekage. In 1513, he assembled forces comprised of Usami Fusatada and Usami Sadamitsu (father and son) who were lineal retainers of the family of the military governor, Jōjō Sadanori from the main Jōjō clan (who was either a younger brother or nephew), and several clans from the Agakita Group, triggering the Jōjō Revolt. Masatsuna, together with, among others, Honjō Fusanaga, Ayukawa Kiyonaga, Mizuhara Masaie, Kurokawa Kiyozane, Nakajō Fujisuke, Ijimino Kageie, Kaji Harutsuna, and Shibata Tsunasada, supported Sadanori and fought against Tamekage.