A shogunate official of the Bakumatsu era, called a forerunner of modernization and "father of the Meiji era." He traveled to the United States in 1860 as a member of the Japanese diplomatic mission, experiencing Western civilization firsthand. After returning, he led modernization reforms as finance magistrate and foreign affairs magistrate. He spearheaded construction of the Yokosuka Iron Works (now Yokosuka Shipyard), completing Japan's first Western-style shipbuilding facility with French technical assistance. He also worked on fiscal reforms including new tax systems and silk trade organization, strengthening the shogunate's economic foundation. Even after the Battle of Toba-Fushimi he advocated fighting to the last, but was overruled; he retired to farm in Kozuke Province (Gunma). Captured by Meiji government forces, he was beheaded without trial at age forty-one. It is said Saigo Takamori later regretted: "We should not have killed Oguri."

A reform-minded official with sharp foresight and strong executive ability. His loyalty to the shogunate was unwavering, but it was underpinned not by conservatism but by passion for modernization. His unjust death is one of history's tragedies.

The Yokosuka Iron Works continued to serve as the foundation of Japan's modern navy into and beyond the Meiji era. Among historians there is a view that "had the shogunate survived, Japan could have modernized more peacefully under Oguri's reform plans."