Taira no Yoshimasa (平良正)
He mainly worked in Mimori, Hitachi Province (present-day Mimori, Tsukuba City, Ibaraki Prefecture), and he married the daughter of MINAMOTO no Mamoru. When the son of Mamoru, MINAMOTO no Tasuku and others fought against his nephew, TAIRA no Masakado, and Tasuku and his brothers were killed as well as TAIRA no Kunika, TAIRA no Yoshikane, who was the head of the Taira clan as well as Assistant governor of Kazusa Province after the death of his father Takamochi, did not interfere with this, while Yoshimasa did not hesitate to back up the Minamoto clan not Masakado from his own Taira clan, and fought against Masakado. Due to this behavior of Yoshimasa, the feud was fueled up. In October, 935, Yoshimasa led his army in order to defeat Masakado, and sensing this, Masakado immediately departed for the front, and on 21st, they fought against each other in Kawamagari Village, Niihari County, Hitachi Province. After the fierce battle, Yoshimasa was defeated and fled, and the next day Masakado retreated to Toyota County, Shimousa Province (present-day Toyota, Joso City, Ibaraki Prefecture), which was his home.
After that Yoshimasa appealed to Yoshikane of Kazusa Province about Masakado's rebellion. Yoshikane, who was the father-in-law of Masakado and his sponsor, could not turn a blind eye to this, and in June, 936, Yoshikane fought against Masakado at the border of Shimotsuke Province along with Yoshimasa and the son of Kunika, TAIRA no Sadamori, but they were defeated.