This article records tradition as it has been passed down and reported. Its sources are not yet part of the atlas's verified catalogue.
Niwano Nikkyo led Rissho Kosei Kai, the lay Buddhist organization he founded in 1938 with Naganuma Myoko after breaking from Reiyukai, for decades after its founding, and his leadership extended well beyond the movement's own membership. He worked to place Rissho Kosei Kai within a wider interfaith and international dialogue, engagement that reached as far as the Unitarian Universalist movement, a tradition well outside the Nichiren Buddhist lineage his own organization had broken away from.
That interfaith turn set Niwano Nikkyo's later leadership apart from the organization's founding dispute over textual study within Reiyukai. Where the 1938 break had been an argument within Japanese lay Buddhism about how the Lotus Sutra should be studied, his later decades of leadership pushed Rissho Kosei Kai outward into dialogue with religious traditions that shared little of that specific inheritance.
Niwano Nikkyo died in 1999, having led the organization he co-founded from a breakaway study group into a movement engaged in interfaith dialogue on an international scale, a trajectory that carried Rissho Kosei Kai considerably further from its Reiyukai origins than the 1938 founding dispute over sutra study alone would have predicted.