Tsunenosuke Namura was one of the 14 lucky students of Ranald Mac-Donald, the first American who taught English to the Japanese official Dutch interpreters for about seven months while he was imprisoned at Nagasaki in 1848. Gohatiro Namura was the chief interpreter of the first Japanese embassy to the United States in 1860. He was also one of the interpreters when the treaty of peace and amity was signed between the United States and Japan in 1854 through the efforts of Commodore M. C. Perry. At that time Gohatiro already had a certain knowledge of English, and because of this, Tsunenosuke was sometimes mistaken for Gohatiro or his father Sadagoro.
This paper presents the results of the author's research of the Namura genealogy. Tsunenosuke and Gohatiro were two different persons, but were descendants of the same ancestor, Hachizaemon Namura, who started to work as Dutch interpreter in 1640.
The numerous achievements of the members of the Namura family not only in the international relations but also in the teaching and learning of Dutch and English languages during the period of more than 200 years are described.