He was the second head of Myôryû-ji in Kamakura, and the pond on the right hand side of the main temple building there is said to show traces of where he undertook 100 days of training in the pond in the middle of winter.
After a successful mission to Kyushu, where he was named superintendent of the mission, he returned to Kyoto, where he evangelized in the streets, and pressured the Ashikaga shogun to denounce and suppress all other Buddhist sects. He wrote a book called "Risshō Chikokuron" in which he accused the Shogun Ashikaga Yoshinori of poor government, leading to his arrest and torture. Despite his imprisonment, even being forced to wear a searing-hot pot over his head to keep him from proclaiming the rightness of the Lotus Sutra (after which he came to be known as "Pot Head Nisshin" (Nabe kamuri Nisshin)), Nisshin was successful in converting a number of prominent figures, including the head of the Konoe family, the head of the Kanô school of painters, and master sword appraiser Hon'ami Kiyonobu. The Kyoto temple of Honpô-ji, founded by Nisshin in 1436, was destroyed by the shogunate when he was arrested, but was later rebuilt.
- Plaques on-site at Myôryû-ji and Honpô-ji.
- William de Bary, Sources of Japanese Tradition, vol 1, Columbia University Press (2001), 294-295.