Mori Muraharu served as a bushō during the Sengoku and Azuchi-Momoyama periods.  He was a commander of the Awa navy.  Muraharu held the title of Governor of Shima.

Muraharu was born as the son of Mori Motomura.  He was based in Tosadomari Castle in Naruto in Awa.  Initially, he served the Hosokawa family and, later, the Miyoshi family.

In 1582, Chōsokabe Motochika, the sengoku daimyō of Tosa Province, invaded Awa Province and fought against Sogō Masayasu, based in Shōzui Castle, at the Battle of Nakatomigawa.  The conflict lasted for twenty days, resulting in the most casualties from a battle in the history of Awa Province.  Following surrender by Motoyasu, almost all of the surviving lords in Awa followed suit, except Muraharu continued the resistance against the Chōsokabe.

After the invasion of Shikoku by Toyotomi Hideyoshi in 1585, Hachisuka Iemasa, a daimyō and retainer of Hideyoshi entered Awa.  Thereafter, Muraharu became a retainer of the Hachisuka clan while he received recognition of his rights to landholdings of 3,026 koku in Fukui-no-shō in Awa.

Muraharu participated in the Conquest of Kyūshū and the Conquest of Odawara.  While supporting the military exploits of his lord, he was killed in action during the Bunroku Campaign on the Korean Peninsula.