Araki Murahisa served as a bushō during the Sengoku period.  He served as the fourth head of the Araki – an illegitimate branch of the Nihonmatsu clan.  Murahisa was the lord of Kunugiyama Castle in the Adachi District of Mutsu Province.

Murahisa was born as the son of Nihonmatsu Masakuni, the sixth head of the Nihonmatsu clan.  He was later adopted by Araki Ujishige, the head of the Araki clan.

In 1547, following the death of Nihonmatsu Yoshiuji, the eighth head of the clan, his son, Nihonmatsu Hisakuni (later known as Yoshikuni) succeeded him as the next head of the main branch of the Nihonmatsu.  Murahisa served as his guardian.

The genealogical records of the Nihonmatsu clan during this period give rise to numerous theories.  With respect to the Araki clan, from the era of Murahisa, there are overlapping and complicated accounts, making it difficult to ascertain the historical facts.

In addition to the name of Murahisa, he is also referred to in accounts under the names of Moritsugu, Tanehisa, and Tokikuni.  It appears likely that he adopted the name of Tanehisa after receiving one of the characters from the name of Ashikaga Yoshitane, the tenth shōgun of the Muromachi bakufu.  It further appears that the names of Murahisa, along with his son’s name of Hisakuni, are based on a character from the name of Ashikaga Yoshihisa, the ninth shōgun of the Muromachi bakufu.  In the case of Murahisa and Tanehisa, however, the character “hisa” is the second character in the name, so it cannot be concluded that this originated from the shōgun.  Finally, Murahisa was succeeded by his second son, Araki Naotsugu, so, based on the use of the character “tsugu,” it is likely that Murahisa used the name of Moritsugu for a period of time.