Lifespan: 15xx to 6/26 of Keichō 9 (1604)
Clan: Amakasu – served the Uesugi
Lord: Uesugi Kenshin → Uesugi Kagekatsu
Father: Amakasu Yasushige
Wife: Younger sister of Kurogane Kagenobu
Children: Naomasa, Shigemasa
Amakasu Kagemochi served as a bushō from the Sengoku to early Edo periods. As a retainer of the Uesugi clan, Kagemochi was referred to as one of the Four Guardian Kings and as one of the Seventeen Warriors of Echigo. He also served a lord of Masugata Castle in Iizuka and Sanjō Castle, both in Echigo Province.
There are several theories concerning the origins of the Amakasu clan. Kagemochi was the first from the clan to appear in records.
- The Amakasu were associated with the Nitta clan and resided in Kōzuke Province. After the decline of the Nitta, the Amakasu served the Uesugi and Nagao clans.
- The Amakasu originated from Ueda-no-shō in Echigo, served Nagao Tamekage, followed by his son, Nagao Kagetora (later known as Uesugi Kenshin).
- The Amakasu resided in the mountainous area of the Shira Ridge on the border between Kai and Shinano provinces and engaged in game-hunting, and later became retainers of Uesugi Kenshin.
Amakasu Kagetsugu, another retainer of the Uesugi, was a distant relative.
Kagemochi’s year of birth is not recorded in family trees and therefore uncertain. His original name was Nagashige, but later given the name of Kagemochi by his lord, Nagao Kagetora. As a retainer of the Uesugi of Echigo Province, Kagemochi served as the lord of Masugata and Sanjō castles in Echigo. There are ancient legends regarding the castles in which Kagemochi resided, but the records only indicate that he was the commander of Sanjō Castle, and many facts concerning his domain remain unclear.
According to one account written in the Edo period, in the autumn of 1547, Nagao Kagetora (Kagemochi’s lord), constructed a castle on Mount Motodori, and Kagemochi built Sanjō Castle to serve as a temporary fortress until the completion of his lord’s castle.
In 1559, after Kagetora returned to Echigo after marching to the capital of Kyōto, numerous commanders celebrated Kagetora’s achievement by presenting him with a long sword. Kagemochi was a member of a group who offered a gilded long sword. In 1560, Kagemochi participated on behalf of Kagetora in a deployment in the Kantō to pledge support for Uesugi Norimasa, the deputy shōgun of Kantō. He also joined an attack against Hōjō Ujiyasu who was holed up in Odawara Castle. When Kagetora succeeded to the role of deputy shōgun of the Kantō and adopted the surname of the Uesugi, Kagemochi, together with Usami Sadamitsu, Kakizaki Kageie, and Kawada Nagachika, served as a 御先士大将 at the Tsurugaoka-Hachiman Shrine in Kamakura.
In 1561, Nagao Kagetora (later known as Uesugi Kenshin) deployed to Kawanakajima to confront Takeda Shingen of Kai Province at the Fourth Battle of Kawanakajima. In this conflict, Kagemochi was assigned to the rear guard, and established a base near the Chikuma River, engaging in a series of violent clashes against a detached unit of the Takeda army who came down from Mount Saijo. Among the Takeda, many mistakenly believed that Kenshin himself was leading the rear guard. Kenshin avidly praised Kagemochi as one of his brave and ingenious commanders. In the midst of this battle, a ceremony was held at the main base of the Uesugi in which Kenshin himself engaged in a Buddhist rite of burning wooden sticks to ask a deity for victory in battle. Kagemochi, along with Kakizaki Kageie and Naoe Kagetsuna enshrined a statue of a fierce Buddhist diety named Acala as the principal object of worship at the shrine.
After Kenshin died in 1578, a succession struggle arose between his two adopted sons: Uesugi Kagetora (the natural son of Hōjō Ujiyasu) and Uesugi Kagekatsu (the natural son of Nagao Masakage). This was known as the Otate Conflict (Otate no ran). A former retainer of Kenshin named Yasuda Akimoto persuaded another retainer named Shibata Shigeie to side in the dispute with Kagekatsu. Kagekatsu prevailed and took over the clan. In 1582, Shigeie launched a rebellion against Kagekatsu on account of not being adequately rewarded for his earlier contributions. In this conflict, Kagekatsu ordered Kagemochi to protect Sanjō Castle, including a fief of 6,000 koku. In addition, Kagemochi provided support for Kiba Castle and assigned to protect the supply base for attacks on Niigata and Nutari castles. In 1586, Kagemochi joined the second division in an expedition to subjugate the Shibata. Kagemochi commanded the infantry unit positioned in Kasabori, and together with Kawada Norichika, Takanashi Satsuma-no-kami, Chisaka Tsushima-no-kami, and Takenomata Masatsuna, killed enemy commanders and achieved meritorious results. Later, Kagemochi received a letter of commendation from Kagakatsu. In 1595, upon orders from a clan elder named Naoe Kanetsugu, he was appointed to serve as a magistrate for the conduct of land surveys in Izumoda-no-shō, Ōtsuki-no-shō, and Honai in the Gamō District. He joined mandatory relocations of the Uesugi clan to Aizu-Wakamatsu in 1598 and to Yonezawa in 1601 and managed a fief of 1,100 koku. In 1602, he founded the Tenshō Temple in Yonezawa.
Kagemochi died in Yonezawa in the summer of 1604, and his descendants served the Yonezawa clan for generations during the Edo period.