Nichiren Shōnin (1222-1282), the founder of Nichiren Shū (the Nichiren School) was a Buddhist monk in 13th century Japan. Nichiren Shōnin sought to find the quintessence of the Buddha’s teachings. He was ordained at age 15 and studied widely, travelling across Japan to read Buddhist scriptures and to learn from various teachers.
Having studied all the Buddhist schools in Japan at the time, Nichiren Shōnin came to the conclusion that the Lotus Sūtra was the teaching fully revealing the Buddha's highest teaching, and his true mind, and that by practising the Lotus Sūtra, by chanting the Odaimoku (Namu-myōhō-renge-kyō or Devotion to the Wonderful Dharma of the Lotus Flower Sūtra), all people could attain enlightenment.
Throughout his life, Nichiren Shōnin worked for the happiness of all people, and many of his writings survive to this day. They include letters of encouragement to followers and disciples of his, and also remonstrations with the government at that time. He was a truly great reformer of Buddhism, who brought many people to have faith in the teaching of the Lotus Sūtra.
Our school, Nichiren Shū, is a confederation of lineages descending from Nichiren Shōnin’s major disciples. The Head Temple of Nichiren Shū is Kuon-ji on Mt. Minobu, Yamanashi Prefecture in Japan; where Nichiren Shōnin spent the last eight years of his life.