Lifespan: Tenbun 14 (1545) to 5/6 of Genki 2 (1571)
Lord: Hashiba Hideyoshi
Father: Hachisuka Masatoshi
Mother: Yasui-gozen (daughter of Yasu Yahyōe-no-jō Shigeyuki)
Siblings: Masakatsu, Matajūrō, Masanobu, Sumi (wife of Oda Kishichirō), Masamoto, sister (wife of Kajiura Masanori)
Children: Hikoshirō (illegitimate)
Hachisuka Masamoto served as a bushō during the Sengoku period.
In 1545, Masamoto was born as the fourth son of Hachisuka Masatoshi, a powerful kokujin, or provincial landowner, in Owari Province.
Similar to his older brother, Hachisuka Masakatsu, Masamoto served Hashiba Hideyoshi. In 1571, he was killed in action during the Battle of Nagashima in Ise Province. He was twenty-seven years old.
Masamoto had a son named Hikoshirō from a consort. Later, his son adopted the surname of Masuda, becoming Masuda Saizō. His descendants adopted the surname of Seki and served in the Tokushima domain of Awa and Awaji provinces.