In 1989, Yamada Koun Roshi passed away in Japan and the Sanbo Kyodan was reorganized. After a few months, Kubota Ji’un Roshi was elected abbot. A system for training teachers and potential teachers was institutionalized. A four-tier structure emerged: assistant teacher, teacher, associate master, authentic master. The first two were entitled to be called sensei and the latter two Roshi. Kenshukai – teacher’s meetings – started to be held annually.
Koun Yamada became a dharma successor to the renowned Zen master Haku'un Yasutani while maintaining a prominent career in business and public health. He guided the Zen practice of many students including a large number of Roman Catholic priests, monks, and nuns. A former Jesuit priest, Ruben L.F. Habito is professor of world religions and spirituality at Perkins School of Theology, Southern Methodist University, and resident teacher at Maria Kannon Zen Center in Dallas, Texas. A dharma heir of Yamada Koun, he is also the author of "Healing Breath" and other works in Japanese and English.
In 1970 Yamada Koun and his wife Kazue Yamada built San’un Zendo on their family compound, which became the central dojo for the Sanbo Kyodan. It was at San’un zendo that he trained many Western and Japanese disciples in zazenkai and sesshin. Many Christians, including Catholic priests, nuns and laypeople, came to the San’un Zendo for Zen training. For a while during the 1970s Yamada roshi oversaw the Honolulu , becoming teacher to future Dharma heir . He died on September 13, 1989 and had authorized many who had completed the Harada-Yasutani koan curriculum in his lifetime.