Kanamari Chikatsuna served as a bushō during the Sengoku and Azuchi-Momoyama periods. He was a retainer of the Uesugi clan and member of the hatamoto rank which, in the Sengoku period, meant the band of bushi responsible for protecting the war banner of their lord. He had the common name of Kojirō.
The Kanamari clan were kokujin, or provincial landowners, in Awa Province, but moved to Echigo Province to serve the Uesugi clan. From the era of Chikatsuna’s grandfather, Kanamari Masatsuna, the clan was relied upon to serve as diplomats and administrators of dealings with Kyōto.
Chikatsuna was born as the son of Kanamari Sanetsuna. Chikatsuna succeeded his ancestors serving important roles under Nagao Kagetora (Uesugi Kenshin) who was the lord of Echigo. As an official, he was primarily stationed in Kyōto, and while engaging in negotiations with the Imperial Court and the Muromachi bakufu, he approached the Sanjōnishi family and also served in the role of a magistrate for the sale of specialty products from Echigo such as ramie fibre. In particular, transactions involving ramie fibre became a key source of revenue for the Uesugi clan, supporting expeditions by Kenshin in the Kantō.
On 5/12 of Tenbun 21 (1552), Chikatsuna entered Kyōto as a messenger to provide thanks for the conferral upon Kenshin of the titles of Junior Fifth Rank (Lower) and Assistant Director of the Judiciary. In return for the thanks and gifts that he presented to the shōgun family, he received a personal letter from Yoshiteru and a long sword manufactured by Bizen Kunimune and, on 6/28, returned from the capital.
In the autumn of 1553, Chikatsuna worked feverishly for the first visit by his lord, Kenshin, to the capital of Kyōto where he enabled a successful meeting between Kenshin and Emperor Gonara. In 1558, he served as a messenger to send congratulations to Ashikaga Yoshiteru, the thirteenth shōgun of the Muromachi bakufu, following Yoshiteru’s return to Kyōto.
In 1577, accompanying the demise of Yamayoshi Toyomori, the lord of Sanjō Castle, and subsequent reduction in fief and transfer of the Yamayoshi family, Chikatsuna was promoted to serve as the next lord of Sanjō Castle.
In 1578, following the death of his lord, Uesugi Kenshin, during the ensuing succession struggle beseting the Uesugi clan known as the Otate Conflict, initially, Chikatsuna appeared to join Yamayoshi Kagenaga of Kiba Castle to support Uesugi Kagekatsu, but, along with Honjō Hidetsuna of Tochio Castle, he fought on behalf of Uesugi Kagetora. Thereafter, he did not respond to maneuvers by Kagekatsu’s side to lure him away, and attacked the stronghold of Kurotaki Castle. Even after Kagetora took his own life, Chikatsuna continued to resist and, although an offer for a settlement was made, it fell through. In 1580, Yamayoshi Kagenaga solicited the cooperation of former retainers in Sanjō Castle, whereupon Chikatsuna was killed by them.