Through his students Philip Kapleau and Taizan Maezumi, Yasutani has been one of the principal forces in founding western (lay) Zen-practice.

[1] Yasutani saw himself becoming a Zen-priest as destined: There is a miraculous story about his birth: His mother had already decided that her next son would be a priest when she was given a bead off a rosary by a nun who instructed her to swallow it for a safe childbirth.

[1] After a fight with another student he had to leave, and at the age of thirteen he was ordained at Teishinji,[1] a Sōtō temple and given the name Hakuun meaning "white cloud".

[4] He was head of a training-hall for a short time when he was at Zuigan-ji, northern Japan,[1][5][dubious – discuss] but gave this up, preferring instead to train lay-practitioners.

[9] The Sanbō Kyōdan incorporates much of Soto tradition, as well as Rinzai Kōan study, a style Yasutani had learned from his teacher Harada Daiun Sogaku.

Yasutani placed great emphasis on kensho, initial insight into one's true nature,[10] as a start of real practice:[1][note 1] Yasutani was so outspoken because he felt that the Soto sect in which he trained emphasized the intrinsic, or original aspect of enlightenment – that everything is nothing but Buddha-nature itself – to the exclusion of the experiential aspect of actually awakening to this original enlightenment.

[12] Brian Victoria, in his book Zen at War, places this remark in the larger context of the Meiji Restoration, which began in 1868.

Japan then left its mediaeval feudal system, opening up to foreign influences and modern western technology and culture.

It marked the constitution of the Empire of Japan, rapid industrial growth, but also the onset of offensive militarism, and the persecution of Buddhism.

He extracts the words and deeds of Japanese Buddhist leaders from their cultural and temporal context, and judges them from a present-day, progressive, Western point of view.

[web 6]Eventually, in 2000, Kubota Ji'un issued an apology for Yasutani's statements and actions during the Pacific War: If Yasutani Roshi's words and deeds, now disclosed in the book, have deeply shocked anyone who practices in the Zen line of the Sanbô Kyôdan and, consequently, caused him or her to abhor or abandon the practice of Zen, it is a great pity indeed.

For the offense caused by these errant words and actions of the past master, I, the present abbot of the Sanbô Kyôdan, cannot but express my heartfelt regret.

[web 6]As founder of the Sanbo Kyodan, and as the teacher of Philip Kapleau and Taizan Maezumi, Yasutani has been one of the most influential persons in bringing Zen practice to the west.