was the name of two mid-Edo period Japanese individuals who served as the 11th daimyà  of Morioka Domain in northern Japan and the 37th hereditary chieftain of the Nanbu clan.
The first Toshimochi was born on 16 January 1808 as the eldest son of Nanbu Nobusuke, the brother of the 10th daimyà  of Morioka, Nanbu Toshitaka. He was adopted as heir by Toshitaka, and became daimyà  on his death in 1820. As he was still underage, domain affairs were managed by his uncle, Nanbu Nobuchika of Shichinohe Domain. Toshimochi was married to the daughter of Maeda Narihiro of Kaga Domain. However, on 17 September 1821 he died of injuries sustained after falling from a tree in his gardens. As this death occurred before even his first formal audience with the shà Âgun, the clan retainers were concerned that the Shogunate would use this as an excuse to reduce or abolish Morioka Domain, so the death was unreported. Toshimochi's cousin Kitarà Â, of similar age and appearance, was selected as his replacement.
The second Toshimochi was born in Morioka on 19 December 1803 as the third son of Nanbu Nobukiyo, a descendant of Nanbu Toshimi, the 7th daimyà  of Morioka Domain. Shortly after the "real" Toshimochi died, he was renamed and brought to Edo to take his place, and was received in formal audience by shà Âgun Tokugawa Ienari on 15 November 1821. He was confirmed as daimyà  of Morioka, and received the courtesy title of Daizen-no-taifu and junior 4th court rank, lower grade in December of the same year. He was also wed to the first Toshimochi's widow.
Due to his age and the circumstances of his accession, he was unable to quell the factionalism which plagued the domain's politics. The domain also had financial problems in meeting its obligations to the shogunate in Ezo territory. Furthermore, the Sà Âma Daisaku Incident, in which a former Nanbu samurai attempted to assassinate the daimyà  of Hirosaki Domain, Tsugaru Yasuchika occurred in April 1821.
Fearing that the shogunate might demand his life over the incident, Toshimochi appointed Nanbu Toshitada as his heir. In 1825, he travelled to Edo due to illness, and died there at the age of 23. His only child was a daughter (later the wife of Nanbu Toshitomo), and per his will, Nanbu Toshitada became the next daimyo of Morioka.
Morioka Domain on "Edo 300 HTML"