Lifespan: Eishō 16 (1519) to 10/23 of Eiroku 10 (1567)
Lord: Kōno Michinao → Kōno Michinobu
Father: Murakami Yasuyoshi
Wife: Daughter of Kōno Michinao, Tenyū Eiju (daughter of Shishido Takaie)
Children: Son, Tokui Michiyuki, son, Kurushima Michifusa, Murakami Michikiyo, Kōno Michinao (?), Shōkei Myōju (formal wife of Hoida Motokiyo), daughter (wife of Murakami Takeyoshi)
Murakami Michiyasu served as a bushō and retainer of the Kōno clan in Iyo Province during the Sengoku period. Michiyasu was the commander of the Murakami navy and lord of Kurushima Castle.
During Michiyasu’s youth, the Kurushima-Murakami stood as the most powerful family in the Fuchū area of Iyo, but confronted persistent rebellions from the influential Masaoka and Shigemi clans.
In 1541, Ōmishima, the northernmost island in Iyo and site of the largest shrine in Iyo known as the Ōyamazumi Shrine, was subject to an attack by the Ōuchi navy. Upon orders from Kōno Michinao, the head of the Kōno clan, Michiyasu deployed along with security forces including members of the Tokui, Hiraoka, and Imaoka clans. Together with reinforcements from the Noshima-Murakami clan, along with Ōhōri clan (priests of the shrine), launched a counterattack against the Ōuchi navy.
Michiyasu enjoyed the deep trust of Michinao, and became one of his son-in-laws. When Michinao entered into conflict with his son, Kōno Harumichi, Michiyasu sided with Michinao, and was chosen as the successor to the Kōno clan. However, many of the retainers of the family supported Harumichi so Michiyasu and Michinao fled from Yuzuki Castle. According to one anecdote, while under attack from the retainers, Michiyasu stopped Michinao from taking his own life and carried him away to Kurushima Castle. The pair were then attacked at Kurushima Castle, and unable to defend themselves, opted for settlement with the retainers. Although Michiyasu did not become the successor to the clan, he was allowed to use the Kōno family seal and adopt the family name of Ochi.
In the era of Kōno Michinobu, Michiyasu performed a central role on multiple fronts including internal politics, diplomacy, and military affairs, corresponding with officials of the Muromachi bakufu and local clans of influence. In 1555, when Mōri Motonari fought against Sue Harukata at Itsukushima in the Battle of Itsukushima, Michiyasu led a navy in support of the Mōri. Thereafter, he actively cooperated with Motonari and led the naval forces in battle against the Ōuchi and the Ōtomo clans.
In 1567, during the height of a battle against the Iyo-Utsunomiya clan, Michiyasu suddenly became ill and returned to Yuzuki Castle, but was unable to recover and died in the autumn. Prior to this development, he had requested support from the Mōri for the clan. Out of gratitude for the support of the Kōno during the Battle of Itsukushima, Motonari dispatched troops to Iyo and had his army under the command of Kobayakawa Takakage land in Iyo whereupon these forces defeated Utsunomiya Toyotsuna and reinforcements from the Ichijō clan of Tosa Province. This event is known as the Deployment of the Mōri Army to Iyo.
After the demise of Michiyasu, one of his daughters married Hoida Motokiyo, a sengoku daimyō in Aki Province and fourth son of Mōri Motonari. Their son was Mōri Hidemoto, and together with a direct descendant, Kurushima Nagachika, two of MIchiyasu’s grandchildren served as daimyō until the Edo period.
Anecdotes describe Michiyasu’s acts of valor on the battlefield beyond those as a naval commander. During battle against the Shigemi clan, he was left with a hole in his helmet from the spear of an enemy commander but nevertheless killed the commander. In another incident, after hearing that the head of an ally from the Furukōchi clan had been taken by an enemy commander, he grabbed it back from the enemy camp. And, at the Battle of Uwajima, he displayed his courage by plunging into the enemy formation to take the fight to his opponents.