Eisai (1141-1215) was a Japanese monk, who is honored as the founder of Zen Buddhism in Japan. He was born into a family of Shinto priests in Bitchu province (now part of Okayama prefecture) and at 14 entered the monastery of Tendai sect of Buddhism on Mt. Hiei, near Kyoto.
In 1168-1169, Eisai studied Zen teachings and discipline in China at the Buddhist center of Mt. Tientai. He set out from Japan for India in 1187 but was unable to proceed beyond China, where he remained studying Zen. Returning to Japan in 1191 he attempted to promote interest in the Rinzai sect of Zen. At Hakata (Fukuoka), he built Japan's first Rinzai temple, the Shofukuji.
Eisai's efforts to advance Zen were strongly opposed by the monks of the Tendai sect, but this opposition was offset when Shogun Minamoto Yoriie appointed him head of the Kenninji temple at Kyoto in 1202. Eisai agreed to accommodate other Buddhist sects there. The position and prospects of Zen in Japan were vitally strengthened when subsequently he became abbot of the Rinzai temple Jufukuji in Kamakura, the center of warrior power. On his death he was given the Buddhist title Zenko Kokushi.
Eisai reintroduced tea to Japan from China and encouraged its use. He is regarded as the founder of the tea cult in Japan.