Nikkō Shōnin (日興上人; 8 March 1246 – 7 February 1333), Buddhist name Hawaki-bō Byakuren Ajari Nikkō (伯耆房白蓮阿闍梨日興), was one of the six senior disciples of Nichiren and was the former Chief Priest of Kuon-ji temple in Mount Minobu, Japan. Various Nichiren sects in Japan claim to have been founded by Nikkō, the most prominent being Nichiren Shōshū and some lineages within Nichiren Shū.
Nikkō kept meticulous records and highly organized religious practice during his lifetime, and is responsible for much of the records that survive today. Nikkō singularly upheld the doctrine that Nichiren was the True and Eternal Buddha in the Third Age of Buddhism and therefore is considered by schools stemming from Nikkō such Nichiren Shōshū and the Soka Gakkai as the legitimate successor to the ministry and legacy of Nichiren.
Nikko established the Head Temple Taisekiji at Fujinomiya in 1290, as well as enshrining the Dai Gohonzon image. In 1332, four months before his death, he designated Nichimoku Shonin as his successor. The grave of Nikkō remains today in Kitayama Honmonji, Omosu, in Suruga Province where he lived for thirty-six years, establishing a Buddhist seminary that affiliated in the Hokke shū (法華宗) religion. The Koshi-E memorial feast of his death anniversary is commemorated on February 6 (Nichiren Shoshu O-tai-ya) and February 7 (Gosho-to-e ceremony).
Nikkō was born at Kajikazawa in Koma District of Kai Province. His father, Oi-no Kitsuroku was from Totsumi province and later moved to Kai province while maintaining his Samurai career. He died when Nikkō was a child. Nikkō's mother was Myofuku Tsunashima (née Yui) and was from what is now Shizuoka Prefecture. He was raised by his grandfather, Nyudo Yui. As a child, he entered the Tendai temple Shijuku-in, in Fujiwakabacho, Iwabuchi Ichirizuka. He took the acolyte name, "Hōki-bō" and received his education here, which as well as Tendai doctrine, included Chinese classics, Japanese literature, poetry, calligraphy, as well as other subjects.
In 1257, Nichiren visited Jisso-ji Temple closely affiliated with Shijuku-in Temple where he studied various Buddhist sutras in its library for his treatise Risshō Ankoku Ron (立正安国論, English: "On Establishing the Correct teaching for the Peace of the Land"). Nikkō served Nichiren here, and vowed to become his disciple. In addition, Nikkō also accompanied Nichiren on his two exiles.
Nikkō is also credited with preserving many of Nichiren's voluminous writings. He was particularly careful to ensure the survival of Nichiren's many letters written in simple characters (Kana) for uneducated followers. He was also instrumental in gaining Nichimoku to become a junior disciple of Nichiren.
On 8 October 1282, Nikkō became one of the six senior priests whom Nichiren designated to carry on his faith after his death. “On the eighth day of the tenth month, he designated six senior priests to act as key figures and take responsibility for propagation in their respective areas. They were, in order of their conversion, Nisshō, Nichirō, Nikkō, Nikō, Nitchō, and Nichiji”. According to various Nichiren school that claim Nikko as their founder, on October 13, 1282, Nichiren further designated Nikkō the chief priest of Kuon-ji, the temple at Mt. Minobu in Yamanashi Prefecture, where Nichiren had spent the last years of his life as purportedly recorded in a transfer document called Minobu-zan Fuzoku-sho ("Document entrusting Mt. Minobu"); however, the authenticity of this document is disputed by some Nichiren schools. Later that same day, Nichiren died at Ikegami, now part of Tokyo.
At Minobu Nikkō recorded the “lectures on the Lotus Sutra” that the Daishonin gave to his disciples and compiled them as The Record of the Orally Transmitted Teachings (OTT). After the Daishonin’s passing, Nikkō Shōnin collected and copied his teacher’s writings, which he called the Gosho, or honorable writings.
Following Nichiren's 100th day funeral ceremonies, Nikkō left Ikegami on October 21 to carry Nichiren's ashes back to Mount Minobu, arriving on October 25. On the centenarian anniversary of Nichiren's death, Nikkō, the other five senior priests, and their disciples conducted a 100th-day memorial service, after which the others departed for their own territories where they were most active. Nikkō carried out his duties as chief priest of Kuon-ji, teaching disciples and looking after the laity. Central to his work was attending, cleaning and maintaining Nichiren's tomb, and collecting and cataloguing Nichiren's many writings for preservation and perpetuation.
Isolation from other disciples
Latter feelings of animosity and discord grew after the second death anniversary of Nichiren's 100th Day Memorial ceremony (23 January 1283) when, according to Nikko, the rotation system agreed in the "Shuso Gosenge
Kiroku" (English: Record document of founder's demise) and Rembo Cho (English: Rotation Wheel System) to clean and maintain Nichiren's grave, was being abandoned by the other five senior disciples.
By the third anniversary of Nichiren's death (13 October 1284), Nikkō claimed that the other five senior priests no longer returned to Nichiren's tomb in Mount Minobu, citing the deer hoofs and other signs of neglect at the gravesite. In addition, Nikkō accused that after Nichiren's death, the other disciples slowly began to deviate from Nichiren's teachings.
Chief among these complaints was the syncretism by some of the disciples to worship images of both Shakyamuni Buddha while admonishing other disciple priests for signing their names "Tendai Shamon" of the Tendai Buddhist school in the subsequent documents notarized and sent to the Kamakura government. Furthermore, Nikko alleged that the other disciples became condescending towards some of Nichiren's writings because they were not written in Classical Chinese, but in the Japanese Katakana syllabary, which was deemed inferior at the time. Accordingly, Nikko Shonin claimed that the other senior disciples permitted Gohonzons originally inscribed by Nichiren to be buried with lay and priestly disciples, a highly controversial practice accused by the Head Temple Taisekiji to be sacrilegious and impermissible to present time.
The steward of the temple district, Hagiri Sanenaga, who had been converted by Nikkō, also began to commit unorthodox practices which Nikkō deemed to be heretical, such as the following:
The crafting of a standing statue of Shakyamuni Buddha as an object of worship.
The donation of noren shrine curtains and horses to the Mishima Taisha Shinto shrine, at the time an honorary shrine of the Hōjō-clan shogunate.
The procurement of bamboo lumber for the Shinto Gassan Shrine.