Genju Keian was a Zen monk of the late Muromachi period.
Genju Keian was born in 1427 in the province of Nagato.
He entered the Nanzen-ji in Kyoto at the age of nine and became a monk of the Rinzai branch of Zen. In 1467 he accompanied the Japanese embassy to Ming China, where he lived in Hangchow and Suchow and studied the Slicing shu (or Shu citing) and other texts, returning to Japan in 1473. At this time Kyoto had been all but destroyed in the Onin War, which lasted from 1467 to 1477, and to avoid the strife Genju retired to the province of Iwami and later went to Kyushu.
In 1478 he was invited by Shimazu Tadamasa, the lord of Satsuma, to come to his domain and lecture on Confucianism, and in 1481 in cooperation with the Jtaro (chief retainer) of the Shimazu family, Ijichi Shigesada, he brought out an edition of the Ta-hsiieh chang-chii (Japanese: Daigakushokit) by the Sung Neo-Confucian philosopher Chu Hsi, thus becoming one of the first to introduce the doctrines of Neo- Confucianism to Japan. Genju continued to reside in Satsuma and lecture on Confucianism until his death, and the line of scholars that he founded, known as the Satsman gakuha, flourished in the succeeding centuries.