Nichiren Buddhism is named after a Japanese monk from the thirteenth century who placed emphasis on chanting Nam-myoho-renge-kyo, which roughly means 'Honor to the Lotus Sutra of the True Teaching'. Nichiren believed that the Lotus Sutra (an important text of the Mahayana School of teaching) held the true meanings of what Buddha was trying to teach. He became ordained as a monk when he was 16 but entered temple at the age of 11. A series of catastrophes in Japan made him believe that since the Japanese societies stop practicing essential Buddhist teachings the fall of their culture was occurring. He theorized if people began chanting Nam-myoho-renge-kyo it would place wisdom and compassion back into their hearts and ways. He had many followers in his day and even now but his teachings are often frowned upon and chastised. One reason why there is so much controversy surrounding the Nichiren schools is because they believe that their way is the only way even though the Lotus Sutra teaches us there are many different ways.
The practice of Nichiren Buddhism has spread all around the world. There are centers for practice and there are many celebrities who practice this path as well (Orlando Bloom from Pirates of the Caribbean is one.) Practitioners recite Nam-myoho-renge-kyo in front of a scroll called the Gohonzon. This practice is called Gongyo or diligent practice. It is recited in the morning and evening. As I stated previously, the Lotus Sutra is the most important text in Nichiren Buddhism. There are links at the bottom of this article for the Lotus Sutra and Nichiren writings for further study.
One should also not that there are different schools of Nichiren. The Lotus Sutra teaches us that there are many different paths to enlightenment which reflects the many different schools of belief not only in Nichiren Buddhism but all of Buddhism. Some schools of Nichiren include Nichiren Shu, Soka Gakkai and Nichiren Shoshu.
I am not a practictioner of Nichiren so this article has been based on research that I have done on my own. I welcome any and all comments from Nichiren Buddhism! Here are some links I have found helpful in my research:
What is the Buddhism of Nichiren? and Soka Gakkai International
Reading the Lotus Sutra could benefit anyone.