Monjūjo Masatsura served as a bushō during the Azuchi-Momoyama and early Edo periods.

The Monjūjo were a key member of a group known as the Fifteen Castles of Chikugo comprised of fifteen high-ranking kokujin, or provincial landowners, based in Chikugo Province under the command of the Ōtomo clan of neighboring Bungo Province during the Sengoku period.

Masatsura was born as the lineal heir of Monjūjo Munekage.  Masatsura served the Kobayakawa clan and, later, the Katō clan of the Kumamoto domain. Next, he served the Tachibana clan of the Yanagawa domain as a guest with a stipend of 500 koku.  Masatsura served as a commander of ashigaru, or lightly armored foot soldiers.

While serving as a retainer of the Kobayakawa clan, Masatsura’s father, Munekage, was killed in action during the Bunroku Campaign on the Korean Peninsula.  Owing to his youth, he was left to wander.  In 1598, he entered the Yanagawa domain and served Tachibana Muneshige (a cousin of Masatsura’s mother).  In 1599, he received a stipend of 1,000 koku.

In 1600, at the Battle of Sekigahara, Masatsura accompanied Muneshige, participating in an assault on Ōtsu Castle.  Afterwards, he received a certificate of commendation for his efforts.  Owing, however, to the defeat of the Western Army with which Muneshige affiliated, after the war, Muneshige was removed from his position while Masatsura’s fief of 1,000 koku was confiscated.

Thereafter, responding to an invitation from Katō Kiyomasa, Masatsura joined Muneshige and entered Higo Province.  In 1602, Muneshige departed from Higo but Masatsura did not accompany him and remained in service of Kiyomasa.  In 1621, Masatsura returned to Yanagawa in Chikugo from Higo and served Muneshige while treated as a guest.  The Yanagawa domain, however, had been reduced from 132,000 koku to 109,000 koku, so Masatsura received a stipend of 500 koku and was not initially assigned to a unit but later served in one of the larger units led by Yashima Uneme.  Separately, his eldest son, Yasutoki, received boarding and 150 koku.

In 1637, Masatsura died of illness and was succeeded by Yasutoki.  His second son, Machino Shigenari, started a cadet family based on a division of landholdings with a yield of 500 koku.