Lifespan: Eishō 13 (1516) to Eiroku 10 (1567) (?)
Title: Governor of Noto
Clan: Aiki branch of the Yoda clan
Lord: Ōi Sadataka → Takeda Shingen
Children: Son, Ichibei (Jōrin), daughter (formal wife of Sanada Masateru)
Aiki Masatomo served as a bushō during the Sengoku period.
Born in 1516, Masatomo was a member of the Aegi-Yoda clan, a branch of the Yoda clan descended from the Seiwa-Genji clan. He was a member of the kunishū, or provincial landowner, in the Saku District of Shinano Province and the lord of Aiki Castle in the Saku District. He may have been an elder of the Iwamurada-Ōi clan in the Saku District. Later, he served as a retainer of the Kai-Takeda clan. There is a theory that he was an elder of Ōi Sadataka, the lord of Nagakubo Castle in Shinano.
On 12/10 of 1542, Masatomo tendered his younger brother as a hostage in anticipation of serving the Takeda clan. Masatomo is believed to have started serving the Takeda in 1543 after Takeda Harunobu (later known as Shingen) invaded Shinano and defeated Ōi Sadakiyo.
Masatomo was deeply trusted by Harunobu and, soon after coming to serve, was appointed as the chamberlain of Taguchi Castle with a garrison of eighty mounted soldiers. In 1561, at the Fourth Battle of Kawanakajima, Masatomo participated as a member of the detached unit.
After the battle, Masatomo was asssigned to provide security for the Zenkōji Basin in Shinano. He maintained a residence in the foothills of Yokoyama Castle in Zenkōji. There is an Aiki boulevard near the ancient Hokkoku Road that ran nearby.
Masatomo is believed to have died in 1567 at the age of fifty-two.
Masatomo cultivated close relations with Sanada Yukitsuna who was another landowner in Shinano serving as a retainer of the Takeda. His eldest daughter married Sanada Masateru (the second son of Yukitsuna). Moreover, Masatomo’s second son, Ichibei married the daughter of Yamagata Masakage. Ichibei adopted the name of Jōrin, and, in other sources, is referred to as Yoda Masatomo.
During the Tenshō Jingo Conflict in the third month of 1582, Jōrin served the Gohōjō clan. During the Conquest of Odawara in 1590, he raised arms from Shiraiwa Castle in the Saku District, but lost to Sanada Masayuki and Maeda Toshiie of the Hokkoku army.