The Sanb˘ky˘dan (Three Treasures Association) is a contemporary Zen movement that was founded by Yasutani Hakuun (1885-1973) in 1954. The style of Zen propagated by Sanb˘ky˘dan teachers, noteworthy for its single-minded emphasis on the experience of kensh˘, diverges markedly from more traditional models found in S˘t˘, Rinzai, or Oobaku training halls. ... [I]n 1954 Yasutani Hakuun (1885-1973), the Zen priest whose teachings are featured in The Three Pillars of Zen, severed his formal ties to the S˘t˘ school in order to establish an independent Zen organization called the Sanb˘ky˘dan, or "Three Treasures Association." The influence exerted by this contemporary lay reform movement on American Zen is out of proportion to its relatively marginal status in Japan: modern Rinzai and S˘t˘ monks are generally unaware of, or indifferent to, the polemical attacks that Yasutani and his followers direct against the Zen priesthood. Orthodox priests are similarly unmoved by claims to the effect that the Sanb˘ky˘dan alone preserves the authentic teachings of Zen. ...
The only acceptable "solution" to the mu k˘an in the Sanb˘ky˘dan is a credible report of a kensh˘ experience, and beginning students are subject to intense pressure during sesshin -- including the generous application of the "warning stick" (ky˘saku or keisaku) -- in order to expedite this experience. The unrelenting emphasis on kensh˘ and the vigorous tactics used to bring it about constitute the single most distinctive (and controversial) feature of the Sanb˘ky˘dan method. Eido Shimano, recalling Yasutani's first sesshin in Hawaii in 1962, writes:
The night before sesshin started, Yasutani Roshi said to the participants, "To experience kensho is crucial, but we are so lazy. Therefore, during sesshin we have to set up a special atmosphere so that all participants can go straight ahead toward the goal. First, absolute silence should be observed. Second, you must not look around. Third, forget about the usual courtesies and etiquette" . . . He also told the participants, and later told me privately as well, of the need for frequent use of the keisaku. That five-day sesshin was as hysterical as it was historical. It ended with what Yasutani Roshi considered five kensh˘ experiences.
(Nyogen et al. 1976, pp. 184-85)
While Yasutani's successors are considerably more reserved in their use of the ky˘saku, the emphasis on kensh˘ has not diminished, prompting one student of Yamada to refer to the San'un Zend˘ as a "kensh˘ machine" (Levine 1992, p. 72).