Lifespan: 15xx to 15xx
Title: Governor of Mimasaka
Bakufu: Muromachi – hōkōshū (military organ of the bakufu)
Lord: Kizawa Nagamasa → Hatakeyama Masakuni → Hatakeyama Takamasa → Hatakeyama Akitaka
Father: Nakamura 圓賀
Children: Nojiri Muneyasu
Yasumi Munefusa served as a bushō during the Sengoku period. He was a retainer of the Hatakeyama clan and served as the lord of Iimoriyama Castle.
Munefusa is surmised to be the natural son of Nakamura 圓賀 and, later, adopted by the Yasumi clan, but his origins are not certain. An individual named Yasumi Ukon (Nobukuni) or Yasumi Shinshichirō appearing in records from the same period is regarded to be a different person from another branch of the family.
Initially, Munefusa operated along with Takayama Hiroyori, a kokujin, or provincial landowner, in Yamato. First, he served under the command of Kizawa Nagamasa who wielded influence in the three upper districts of Yamashiro. Prior to the Battle of Taihei Temple in 1542, Munefusa pledged his support to Hosokawa Harumoto and, thereafter, served the Hatakeyama clan.
On 5/5 of Tenbun 20 (1551), Yusa Naganori (who held sway over the Hatakeyama family) was assassinated by Kayafuri Katatsugu. On 2/21 of Tenbun 21 (1552), Munefusa invited Katatsugu to Iimoriyama Castle under the pretext of a tea ceremony and then had him killed. He proceeded to eliminate the Kayafuri clan and expel the Nojiri clan, while Naganori’s younger brother (who was a monk at the Negoro Temple) was killed by the Miyoshi clan. Munefusa backed a member of the Yusa clan named Yusa Ōfuji, shoring-up his foundation. He backed Hatakeyama Takamasa as the military governor and, together with Tange Moritomo, became a leader in the family. He also sent a child for adoption by the Nojiri clan who was then named Nojiri Muneyasu. Munefusa had a falling out with Takayama Hiroyori, who was a collaborator of Munefusa for many years, and, before long, Hiroyori was killed. After Ōfuji ceased from further action, Munefusa gained authority.
Munefusa’s role as a deputy military governor only appears in military chronicles from later eras. In one account, from the perspective of the Hongan Temple, the status of Munefusa in the Hatakeyama clan was lower than other senior retainers from the Yusa, Tange, and Hashirii clans. Notwithstanding how much power Munefusa wielded, he was not at the level of a deputy military governor. More likely, at this time, Yusa Ōfuji would have been at that level.
In 1553, during a confrontation between Ashikaga Yoshiteru (the thirteenth shōgun of the Muromachi bakufu) and Miyoshi Nagayoshi, Munefusa aligned with the Miyoshi and, together with Tange Moritomo, headed-out as reinforcements. During the Eiroku era (1558 to 1570), he planned riparian works at Sayama Pond. Munefusa, however, gradually came into conflict with his lord, Hatakeyama Takamasa. In 1558, Munefusa fled to Kii Province. In the eighth month of 1559, Munefusa fought against Miyoshi Nagayoshi who received support from Takamasa, but was defeated and fell into ruin in Yamato. After returning to Takaya Castle, Takamasa had a falling out with Nagayoshi and, in the fifth month of 1560, Munefusa reconciled and returned to his service. Thereafter, he obeyed Takamasa and cooperated in battles against the Miyoshi clan including the Battle of Kumeda and the Battle of Kyōkō Temple but was defeated and, along with Takamasa, ruined.
In 1565, following the assassination of Ashikaga Yoshiteru in the Eiroku Incident, Munefusa worked on behalf of the bakufu, quickly requesting support to back Yoshiteru’s younger brother, Kakukei (later known as Ashikaga Yoshiaki), as the successor, and providing updates to Uesugi Kenshin of Echigo in regard to the status of affairs in the Kinai. Around this time, he adopted the Yusa surname. As the Miyoshi Group of Three came into conflict with Matsunaga Hisahide, Munefusa joined Hatakeyama Takamasa and Hatakeyama Akitaka (siblings) to ally with Hisahide, and aimed to recover the Kinai but were defeated. In 1568, Yoshiaki entered Kyōto with the backing of Oda Nobunaga and became the fifteenth and final shōgun of the Muromachi bakufu. Munefusa, along with Takamasa and Akitaka, submitted to his rule and finally returned to Kawachi.
In 1569, Munefusa joined Yusa Nobunori to back Takamasa’s younger brother, Akitaka, as the head of the family and Takamasa was ousted again. This ouster, however, appears in only one chronicle and appears to be an adaptation of the dispute that occurred in 1558. After Ashikaga Yoshiaki went to Kyōto, there are few traces of Takamasa and Munefusa jointly governing Kawachi. It is surmised that each of them amicably transferred the headship of their respective clans (Takamasa to Akitaka and Munefusa to Muneyasu) while residing in the capital.
In the first month of 1570, Munefusa was chosen to serve as a member of the military organ of the bakufu known as the hōkōshū, but his whereabouts thereafter are unknown.
In the fifth month of 1571, when Munefusa was in Katano Castle, an individual named Yasumi Ukon was lured by Matsunaga Hisahide (who had secretly betrayed Oda Nobunaga) to Tamonyama Castle and forced to kill himself, but Ukon was not the same individual as Munefusa.
In 1577, at a tea ceremony held by Tsuda Sōgyū, appreciation was given to items inherited from Munefusa so he appears to have died around this time.