Yamada Ryoun Roshi is the current, and fourth, abbot of Sanbo-Zen.
“Yamada Ryôun Roshi was born in 1940 in Manchuria, and became Yasutani Roshi’s disciple when he was 16 years old. In 1978 he finished his formal Zen training under Yamada Kôun Roshi, and in 1985 he succeeded to the Dharma of Kôun Roshi. As a Zen Master (shôshike) of the Sanbô-Zen he took over the office of the Abbot of the Sanbô-Zen in October 2004.” ~ excerpt from Sanbo Zen official website
“Ryoun Yamada, aka Yamada Ryoun or Yamada Masamichi, the son of the late Yamada Koun, is the current Zen master of San’un Zendo in Kamakura, Japan and the Abbot of the Sanbo Zen school of Zen Buddhism. Sanbo Zen is a lay organization of Zen, so Yamada also worked at Mitsubishi Bank and Mitsubishi Securities. Currently he heads the Itoki Corporation. …” ~ from the Wikipedia page on Ryoun Yamada