Kanamitsu Munetaka served as a bushō during the Sengoku period, as a retainer of the Ukita clan, and as lord of Ishiyama (Okayama) Castle in Bizen Province.  He was either the son or younger brother of Nose Yoriyoshi.

Munetaka was adopted by Kanamitsu Bizen, a kokujin, or provincial landowner, affiliated with the Matsuda clan.   Bizen did not have a son so Munetaka became his heir.  Munetaka followed after his father in service of the Matsuda. However, after the Matsuda and Ukita clans reconciled their differences around 1564, Munetaka joined with the Uragami.  When the neighboring Mimura clan detected a plan by the Uragami to deploy forces to Bitchū Province, the Mimura made a preemptive attack against Munetaka’s base at Ishiyama Castle.  There were not enough soldiers to mount a defense of the castle, so Munetaka reluctantly surrendered and came under the command of the Mimura.

In 1567, after the defeat of the Mimura clan at the Battle of Myōzenji, Munetaka was stationed at the home base of the Ukita clan at Kameyama Castle and came under the command of the Ukita. 

Ukita Naoie, the head of the Ukita clan and a sengoku daimyō, desired to build a town in the foothills below Ishiyama Castle.  For uncertain reasons, in 1570, Naoie accused Munetaka of colluding with the Mōri and refused an explanation.  Munetaka then drafted a note stating that he would turn-over Ishiyama Castle on the condition that, after his death, his fief be given to his children, Kanamitsu Bunemon and Kanamitsu Tarōemon (900 koku each, and 400 koku for the castle guards), whereupon he committed seppuku.

Munetaka was ardently religious. In the Tenbun era (1532 to 1555), he invited high priests from Mount Hiei to Kanamitsu-Okayama Temple on the grounds of Ishiyama Castle.