Nikko achieved brilliant success working actively in shakubuku (a method of propagating Buddhism which was practiced by Nichiren Daishonin) as one of the six old monks of close disciples of the founder of the Sect, and established a powerful organization for religious society especially in Suruga Province.
日興は、宗祖の本弟子六老僧の1人として積極的な折伏に目覚しい成果をあげ、特に駿河国において強力な教団組織を創りあげた。