is a Japanese Buddhist religious movement based on the teachings of the 13th-century Japanese priest Nichiren as set into motion by its first three presidents Tsunesaburo Makiguchi, Josei Toda and Daisaku Ikeda. It is the largest of the Japanese new religions and holds the largest membership among Nichiren Buddhist groups. From 1952 to 1991 it shared an association with the Nichiren Shoshu Buddhist sect. The Gakkai bases its teachings on the Lotus Sutra and places chanting "Nam Myoho Renge Kyo" at the center of devotional practice. The movement is involved in peace activism, education and politics.