Lifespan: 15xx to 15xx
Title: Governor of Iga, Junior Fifth Rank (Lower), Governor of Owari
Lord: Takeda Nobutora → Takeda Harunobu
Father: Atobe Munekatsu
Children: Katsusuke, Yoshiyasu, two daughters
Atobe Nobuaki served as a retainer of the Takeda clan of Kai Province. He was the eldest son of Atobe Munekatsu and father of Atobe Katsusuke. Nobuaki entered the priesthood and adopted the name of Hankeisai. Nobuaki served during the era of Takeda Nobutora and Harunobu (Shingen) and governed nine villages in Kai.
The Atobe descended from the Ogasawara clan, the military governor of Shinano Province, originating from the village of Atobe in Shinano. In 1416, Takeda Nobumitsu, the military governor of Kai Province, was decimated in a conflict known as the Uesugi-zenshū no ran. The Muromachi bakufu assigned Takeda Nobumoto and, thereafter, Takeda Nobushige who had entered the priesthood on Mount Kōya, to become the next shugo of Kai. The bakufu further ordered Ogasawara Masayasu, the military governor of Shinano, to support the return of the Takeda to Kai. Masayasu then dispatched the Atobe to serve as the deputy military governor to the Takeda, causing the Atobe to settle in Kai. In 1465, Takeda Nobumasa eliminated Atobe Kageie, and expelled the Atobe from Kai.
A writing from 1553 notes Nobuaki in connection with other members of the Atobe clan. Nobuaki’s name frequently appears as a signatory on official tax exemptions, with only Komai Kōhakusai, a close associate of Harunobu, appearing more often. Hankeisai (Nobuaki’s name after entering the priesthood) appears in a writing from 1567, after which his son’s name, Katsusuke, appears frequently. Nobuaki is last noted as a signatory in a writing from 1570.
A Buddhist mortuary tablet noting Nobuaki Iga-no-kami and spouse is enshrined at the Hankei Temple in Kōfu.