The Ōbaku-shū (黄檗宗) is one of several schools of Zen in Japanese Buddhism, in addition to Sōtō and Rinzai.
Often termed the third sect of Zen Buddhism in Japan, it was established in 1661 by a small faction of masters from China and their Japanese students at Manpuku-ji in Uji, Japan.
Today Manpuku-ji serves as the Ōbaku's head temple, with 420 subtemples spread throughout Japan as of 2006. In addition to their contribution to the culture of Zen in Japan, the Ōbaku also "disseminated many aspects of Ming-period culture" in the country. Many of the monks who came from China were accomplished calligraphers, and Obaku's founder Yinyuan Longqi and two other Ōbaku masters, Mokuan Shōtō and Sokuhi Nyoitsu, became known as the Ōbaku no Sanpitsu (or, the "Three Brushes of Ōbaku"). Author Steven Heine writes, "Areas where the influence of — or the reaction to — Ōbaku left an imprint on Japanese Buddhism is manifold, and its impact even reached the fields of Japanese cultural techniques, such as printing and painting.Chinese medicine and architecture were also introduced, as was the practice of "spirit writing", the latter practiced by Ōbaku monks who were said to communicate with Chen Tuan.