The Shōshinkai (正信会: "correct faith association") or Nichiren Shoshu Shōshinkai is a Japanese Nichiren Buddhist group formed in July 1980 by over 200 Nichiren Shōshū priests (mostly the disciples of the former High Priest Nittatsu Hosoi) and their followers who were critical of the Sōka Gakkai.
For several years during the 1970s, the Sōka Gakkai undertook a number of activities and propagated several notions that many in the Nichiren Shōshū priesthood and laity saw as gradually increasing deviations from traditional Nichiren Shōshū doctrine. As these incompatibilities grew, more and more Sōka Gakkai members began to quit the lay organization and associate themselves directly with local temples, and many priests began to openly encourage them to do so. Eventually sentiment within the priesthood and traditional lay organizations grew so strong that a split became imminent, and, at a special leaders meeting held at Nichiren Shōshū Head Temple Taiseki-ji on November 7, 1978, Sōka Gakkai's leadership apologized to the priesthood and promised to correct the incompatibilities and never deviate from Nichiren Shōshū doctrine again.
On April 24, 1979, Sōka Gakkai's President Daisaku Ikeda stepped down to take responsibility for the incident. At the 40th General Meeting of the Sōka Gakkai on May 3, 1979, the contemporary high priest, 66th High Priest Nittatsu Hosoi, declared his decision to accept the organization's apology and forgive the matter on condition that Sōka Gakkai observe its promise to uphold Nichiren Shōshū doctrine. Separately, he instructed priests to stop open criticism of Sōka Gakkai and to cease encouraging Sōka Gakkai members to affiliate themselves directly with the temples.
On July 22, 1979, High Priest Nittatsu suddenly died without naming his successor and Shinno Abe, at that time young priest, insisted that he was given permission secretly to be the next High Priest by Nittatsu before he had died and succeeded him as the 67th High Priest, Nikken Abe. He changed his predecessor's policy and gave Sōka Gakkai a chance to cooperate with him. But the priests (who were mainly the disciples of the former High Priest) who later formed the Shōshinkai disagreed, claiming Sōka Gakkai had only taken its deviations underground.
They continued their campaign of criticism and formed Shōshinkai to organize their efforts into a movement. Despite repeated admonitions from the new High Priest Nikken and Nichiren Shōshū leadership to cease and desist, Shōshinkai went ahead with a major rally on August 24, 1980. For this defiance, High Priest Nikken and Nichiren Shōshū leadership punished a number of priests for their involvement, including five excommunications which Shōshinkai priests claims ineffective because that punishment was done by the 'fake' High Priest.