Otsuki Gentaku

• Japanese: 大槻玄沢 (Ootsuki Gentaku)

Ôtsuki Gentaku was a Rangaku scholar.

His 1799 Ransetsu benwaku (蘭説弁惑, "Clarifying Errors in Theories about the Dutch") was perhaps the first major Japanese work to assert that Africans were "no different from the rest of mankind," and that they were not, on the whole, as a group, less intelligent or otherwise of inherently lower birth, but rather that Africans, like anyone else, included "the noble and the lowly, ... the wise and the foolish."

Along with Shimura Hiroyuki, Ôtsuki produced in 1807 a set of interviews called Kankai ibun, which recorded the experiences of a group of Japanese castaways who had seen the Atlantic, the Straits of Magellan, and Hawaii.