- Other Names: 藤七郎 (Tôshichirô), 通義 (Tsûgi)
- Japanese: 矢田部 雲八 or 谷田部雲八 (Yatabe Kumohachi)
Yatabe Kumohachi was a Mito han retainer known for his involvement in factional politics within the domain, and for efforts to weaken and seize control from lord Tokugawa Yoshiatsu and his father (former lord of Mito) Tokugawa Nariaki.
In 1855, Yatabe, alongside a number of others who favored the politics of imprisoned former Mito Tokugawa clan karô Yûki Toraju, conspired to somehow weaken Yoshiatsu and Nariaki and reclaim control of domain administration from them. Their plot was discovered, however, and Kumohachi fled along with his younger brother, Ômine Shôzô.
On 1856/1/25, a number of their co-conspirators were imprisoned by Yoshiatsu's administration. Nearly a year later, on 1856/12/17, Yatabe and his brother were discovered at Fujieda post-station along the Tôkaidô highway, and arrested on the shores of the Ôi River. In 1857/8, Kumohachi was sentenced to beheading, and his compatriots punished as well.
- Ishin Shiryô Kôyô 維新史料綱要, vol 2 (1937), 162, 281, 404.