The Okochi Clan (大河内氏)
The Okochi clan is part of the Seiwa-Genji (Minamoto clan) and Settsu-Genji (Minamoto clan), and is said to have been established when Akitsuna, the grandson of MINAMOTO no Yorimasa, moved to Okochi-go, Nukata County in Mikawa Province (which some have asserted to be the present-day Aza-Okochi, Ohira-cho, Okazaki City, Aichi Prefecture) and called himself Okochi. Akitsuna's father was MINAMOTO no Kanetsuna. However, the clan's activity and family tree aren't clearly defined, and the name "Akitsuna" doesn't appear in any reliable source, so to some the stated origin is only an assumption. Masatsuna MATSUDAIRA became an adopted son of the Nagasawa Matsudaira family, which was said to be the Nitta clan branch of the Kawachi Genji (Minamoto clan), which in turn belonged to the House of Tokugawa; since then, the clan has been known as the Okochi Matsudaira family. During the Edo period the family members held the ranks of daimyo (Japanese territorial lords) or hatamoto (samurai in the direct service of Tokugawa family), and produced prominent characters such as Nobutsuna MATSUDAIRA, a roju (elder) whose nickname meant "The Wisdom of Izu." During the Meiji period, the clan restored the Okochi name.
The family history before Masatsuna was adopted by the Nagasawa Matsudaira family.
MINAMOTO no Akitsuna, who lost his grandfather MINAMOTO no Yorimasa and father MINAMOTO no Kanetsuna in the War of Prince Mochihito of 1180, fled to Okochi-go, Nukata County, in Mikawa Province (now near the Okazaki interchange of the Tomei Highway) with his mother. Yoshiuji ASHIKAGA (1189 - 1255), the third head of the Ashikaga family, was later appointed to serve as the military governor of Mikawa Province by the Kamakura bakufu (Japanese feudal government headed by a shogun) as a reward for his contributions during the Jokyu War of 1221. Akitsuna joined the service of Yoshiuji ASHIKAGA, who was Akitsuna's junior in age. This MINAMOTO no Akitsuna is the first Akitsuna OKOCHI. His son, Masatsuna (Masaaki) OKOCHI, is said to have been retained by Yasuuji ASHIKAGA. Later, the Okochi family held the post of chief retainer of the Kira family, which was part of the Ashikaga family tree. It operated from Teratsu-jo Castle in the Hazunokori area (now Teratsu-cho Town, Nishio City). The castle is also called Fusecho-jo Castle due to the design of the formal crest that represented the Okochi clan. A branch of the family came to take the post of daikan (regional administrator) of the Hikumaso, in Totoumi Province (now Hamamatsu City, Shizuoka Prefecture) which was the territory of the Kira clan. Sadatsuna OKOCHI joined hands with the Shiba clan and determinedly fought against the Imagawa clan.
Among the members of the family branch that split prior to the modern times, there was a family of hatamoto that passed the name 'Zenbei OKOCHI' down through the generations.
Family history after adoption by the Nagasawa Matsudaira family
In 1587, Ieyasu TOKUGAWA arranged for Masatsuna MATSUDAIRA, the second son of Hidetsuna OKOCHI, to become an adopted son of Masatsugu MATSUDAIRA, who belonged to the Nagasawa Matsudaira family group. Masatsuna rose through the ranks as hatamoto and eventually became the daimyo of the Tamatsuna domain in Sagami Province, with 22,000 koku. This is why the Okochi family is allowed to use the Matsudaira name and is therefore called Okochi Matsudaira. During the Edo period, there were three daimyo in the family. A daimyo in one of the Okochi family branches used the name "Matsudaira Izunokami." Nobutsuna MATSUDAIRA, who was the lord of the Oshi domain in Musashi Prrovince (Gyoda City, Saitama Prefecture) and of the Kawagoe domain (Kawagoe City, Saitama Prefecture), and who was revered as the "Wisdom of Izu," was a member of the Okochi clan. From the Meiji period, families that were hatamoto also reverted to the Okochi name. The three daimyo families were given peerage and became viscounts.
Decendents include Masatoshi OKOCHI, a physicist who was the director of the Science and Chemistry Institute.
The family crest
The formal crest is a butterfly with 16 chrysanthemums (commonly called an Izu butterfly), and the alternative crest is three fans. The alternative crest of one of the branches, in the Takasaki domain, Kozuke Province (Takasaki City, Gunma Prefecture), is called Takasaki-ogi crest, and the school crest of Takasaki Economics University, which is a public university run by Takasaki City, was created from this crest.