Lifespan: Eiroku 9 (1566) to 4/14 of Genna 2 (1616)
Other Names: Gengorō, Jūemon
Clan: Sena (descended from the Imagawa clan of the Ashikaga branch of the Seiwa-Genji)
Father: Sena Nobuteru (Ujiakira)
Mother: Daughter of Katsurayama Ujimoto
Wife: Member of the Koide clan
Children: Kiyosada, Yoshihisa
Sena Masakatsu served as a bushō during the Azuchi-Momoyama and early Edo periods. He served Tokugawa Ieyasu and became a hatamoto, or direct retainer. He held small fiefs in Yamato, Suruga, and Musashi provinces, in addition to assignments at Edo Castle.
In 1581, at the age of sixteen, he met Tokugawa Ieyasu for the first time. From the second month of 1584, he served as a close associate of Ieyasu and participated in the Battle of Komaki-Nagakute. Thereafter, he received a fief of 300 koku in Yamato Province.
On 3/11 of Tenshō 18 (1590), 190 koku from his fief was moved to the village of Sena in the Ihara District of Suruga Province. After Ieyasu moved to the Kantō, his fief changed to the Iruma District of Musashi Province. On 5/17 of the same year, he received a letter bearing the scarlet seal of the shōgun.
In 1600, he served on behalf of the Eastern Army at the Battle of Sekigahara and, later, was in the ranks of the ōban, one of five military branches formed by the Edo bakufu comprised of reserve troops drawn from hatamoto, or direct retainers of the bakufu.
Masakatsu died on 4/14 of Genna 2 (1616) at the age of fifty-one. He was buried at the Shōgen Temple in Ushigome in Edo.
Based on genealogical records, he had two sons, Sena Kiyosada (a hatamoto in the Edo period) and Sena Yoshihisa (Masashige). Yoshihisa’s common names were Hachirōemon and Jinzaemon. In 1628, he first met Tokugawa Iemitsu. He started a separate family and became a hatamoto. He served as a member of the gojūnin, one of five military branches formed by the Edo bakufu comprised of reserve troops drawn from hatamoto to provide security for the Tokugawa shōgun family and, later, as a guard at Edo Castle. On 9/26 of Keian 1 (1648), he became an attendant to the shōgun. In 1651, however, he was found complicit in the crimes of a subordinate and removed from his position.