On September 12, 1271, Nichiren Shōnin was arrested and taken to the execution grounds on Tatsunokuchi beach. He was saved from death when a mysterious ball of light that flew through the sky frightened the executioner and the other samurai. A messenger from the regent arrived soon after with orders that Nichiren Shōnin was not to be executed in any case but exiled instead. On October 10, 1271, Nichiren Shōnin was sent into exile on Sado Island. At first, he lived in a small broken down shrine in a graveyard called Tsukuhara. It was the hope of his enemies that Nichiren Shōnin would die in the harsh winter of Sado Island without any adequate shelter or provisions.

Nichiren Shōnin did not die, however, but went on to write two of his five most important writings. The first was Kaimoku-shō (Open Your Eyes to the Lotus Teaching) in February 1272, intended to be a memento and an expression of his conviction that despite the persecutions he had faced he was a messenger of the Eternal Śākyamuni Buddha to the people of Japan in the Latter Age of the Dharma. This is now interpreted by the Nichiren Shū to mean that Nichiren Shōnin was implying that he was Superior Practice Bodhisattva, the leader of the bodhisattvas who emerge from the earth who appear in chapter 15 of the Lotus Sūtra and are given the specific transmission of the Wonderful Dharma for the Latter Age in chapter 21.

The second of his five major writings was written a year later. Having impressed the local lord, Lord Shigetsura Honma, Nichiren Shōnin was allowed to move to the residence of a lay priest at Ichinosawa. Now under the protection of the local lord and in more comfortable lodgings, Nichiren Shōnin turned his attention to writing a treatise revealing the correct way of practice and the true focus of devotion for the Latter Age of the Dharma. On April 25, 1273, he completed the second work, whose full title is Nyorai Metsugo Go-gohyaku-sai Shi Kanjin Honzon-shō (A Treatise Revealing the Contemplation of the Mind and the True Focus of Devotion for the First Time in the Fifth 500-year Period After the Death of the Tathāgata). Usually this treatise is referred to simply as Kanjin Honzon-shō (Contemplation of the Mind and the True Focus of Devotion).  It was sent to his lay follower, Toki Jōnin, on the 26th. The cover letter states that the treatise deals with the practice of contemplation of the mind and that it is of utmost importance and should be kept secret and shown only to those with unshakeable faith in the Lotus Sūtra.

In this writing, Nichiren Shōnin explicitly reveals the first two of the Three Great Secret Dharmas of the Original Gate of the Lotus Sūtra: (1) the practice of chanting the Odaimoku or Sacred Title of the Lotus Sūtra, and (2) the establishment of the Eternal Śākyamuni Buddha as the honzon or true focus of devotion for the Latter Age. These first two of the Three Great Secret Dharmas are described in the first two parts of Kanjin Honzon-shō. The third of the Three Great Secret Dharmas is the kaidan or precept platform where one accepts the precept to uphold the Lotus Sūtra. This last is not explicitly referred to or described in Kanjin Honzon-shō, though it is believed to be implicit in Nichiren Shōnin’s discussion of the transmission of the Odaimoku in the Latter Age of the Dharma in the third and final part of Kanjin Honzon-shō.

It should be noted that just three months later, Nichiren Shōnin inscribed the first Omandala (Great Mandala) on July 8, 1275. This was a calligraphic mandala depicting what he had described in Kanjin Honzon-shō.

Much of this treatise assumes a great deal of knowledge of Mahāyāna Buddhism, and specifically T’ien-t’ai Buddhism, on the part of the reader. In fact, the treatise begins with a very technical citation from Great Concentration and Insight by T’ien-t’ai Chih-i (538-597). For that reason, the first few chapters of this commentary will deal with the life and teachings of Śākyamuni Buddha, the development and transmission of Buddhism, and the history and teachings of the T’ien-t’ai school in order to establish the context of Kanjin Honzon-shō itself.