Gudo Wafu Nishijima was born 1919 in Yokohama, Japan. He was drafted by the Japanese army during the Second World War, and was sent as a soldier to Manchuria. Luckily, he never killed anyone, and he was the only survivor from his military group. Nishijima began studying Buddhism and practicing zazen under the guidance of Kodo Sawaki Roshi.
Nishijima Roshi was ordained as a priest in the Soto Zen tradition by Renpo Niwa Roshi, abbot of Eiheiji, and later received the Transmission of the Dharma (traditional teacher status) from him. He combined daily zazen practice and Buddhist studies with work and family life. Nishijima taught that zazen is not only for monks and nuns, but that it is available to all. He was also very interested in learning more about Judaism and Christianity.
In the year 2000, Gustav Ericsson was a theology student from Sweden travelling in Japan looking for zazen teachers. Gustav and Nishijima met in Tokyo and became friends. Gustav shared his thoughts on the Christian tradition, and Nishijima became Gustav's zazen teacher. They kept in close touch, and Gustav visited Nishijima's zazen dojo every year.
In 2004, Gustav received the Transmission of the Dharma from Nishijima, and began arranging zazen meetings and retreats in his hometown Umeň in Sweden. In 2007, while visiting Nishijima in Japan, Gustav came up with the name Anzenkai for an open and religiously independent zazen group and network. Nishijima liked the idea and made a calligraphy of the name. The first Anzenkai retreat was held in 2009, on an island near Umeň.
In 2010, Gustav was ordained as a priest in the Church of Sweden, which is in the Lutheran Protestant tradition. The same year, Gustav and Daniel Pettersson became friends. Daniel had been practicing zazen for several years, and received the Buddhist precepts (Jukai) from Peter Rocca, one of Nishijima's Dharma heirs. In the fall of 2011, Gustav and Daniel began arranging zazen and breakfast every Friday morning at MYA Flow Yoga Studio in Umeň.