Nisshō Inoue was a radical Buddhist preacher of Nichirenism who founded the interwar Japanese far-right militant organization Ketsumeidan . Contrary to popular belief, he was never an ordained Nichiren priest, but was rather a self-styled preacher whose extremist tenets were widely denounced by Japan's mainline Nichiren Buddhist establishment of the time.

Nichiren Buddhism, also known as Hokkeshū, is a branch of Mahayana Buddhism based on the teachings of the 13th-century Japanese Buddhist priest Nichiren (1222–1282) and is one of the Kamakura period schools. Its teachings derive from some 300–400 extant letters and treatises either authored by or attributed to Nichiren.