Kōsen-rufu (広宣流布), a phrase found in the Japanese translation of the Buddhist scripture Lotus Sutra, is informally defined to as "world peace through individual happiness." It refers to the future widespread dissemination of the Lotus Sutra.
The term derives from Lotus Sutra's 22nd chapter: "Propagate this chapter widely throughout the Jambudvīpa in the last 500-year period after my death." Nichiren (1222–1282), the founder of Nichiren Buddhism, took this statement to indicate that the Lotus Sutra is the Law to be declared and widely spread during the Latter Age.
Kōsen means to "widely declare." "Widely" implies speaking out to the world, to an ever-greater number and ever-broader spectrum of people. "Declare" means to proclaim one's ideals, principles and philosophy. The ru (flow) of rufu means "a current like that of a great river," and fu (cloth) means "to spread out like a bolt of cloth." This requires an active and engaged approach of shakubuku, propagation of the Dharma, rather than peaceful retreat or meditative solitude.
Kosen-rufu as peacemaking
Literally, kōsen-rufu means to declare and spread widely the teachings of the Buddha; however, the term "kosen rufu" has come to connote "world peace" based on the Lotus Sutra and Nichiren teachings. The Soka Gakkai is a Nichiren-inspired religious movement headquartered in Japan that has incorporated peace activities its religious practice.
According to the Soka Gakkai, Nichiren stressed the ideal of achieving kōsen-rufu in Buddhist practice because he felt that the quests for personal enlightenment and the peace and well-being of the entire society were inseparable.