Sōka-gakkai has had rapid growth since the 1950s and is the most successful of the new religious movements that sprang up in the 20th century in Japan, but, in following the teachings of the Buddhist saint Nichiren, it belongs to a tradition dating from the 13th century.

As of 2011, the SGI reported active national organizations in 192 countries and territories with a total of approximately 12 million members. The SGI is independent of the Soka Gakkai (the domestic Japanese organization), although both are headquartered in Tokyo.

November 28, 1991, marked the day that the Soka Gakkai was excommunicated from the Nichiren Shoshu. To Soka Gakkai members, however, this day marks the day they achieved their spiritual independence.

Soka Gakkai Nichiren Buddhism, however, believes that the fundamental cause for revealing the ultimate potential of life, or Buddha nature, can diminish the influence of negative karma in the present lifetime. Ikeda explains that negative karma is subsumed in the world of Buddhahood and is purified by its power.