Sugenoya Masasada served as a bushō during the Sengoku and Azuchi-Momoyama periods.  He was a retainer of the Oda clan, sengoku daimyō of Hitachi Province.

In 1518, Masasada was born as the son of Sugenoya Katsusada, a retainer of the Oda clan.  The Sugenoya called themselves descendants of the Akamatsu clan, in addition to the Ki clan and Sugawara no Michizane, a noble, scholar, and politician from the Heian period.

Similar to his father, he loyally served his lord, Oda Ujiharu.  In the fourth month of 1564, Masasada made significant contributions while serving in the vanguard forces of the Oda army against the Uesugi army led by Uesugi Kenshin at the Battle of Sannōdō.  Notwithstanding his efforts, the conflict ended in defeat for the Oda.

After Ujiharu lost Oda Castle to the Satake clan, Masasada welcomed Ujiharu to his base at Tsuchiura Castle and recaptured Oda Castle several times.  In 1583, however, Ujiharu submitted to the Satake clan so Masasada was compelled to follow him.

Later, he entered the priesthood, adopting the monk’s name of Zenkyū.

Masasada died in 1592.