[During the Sado period,] Nichiren elaborated three aspects of this “secret Dharma”—the daimoku, the object of worship, and the ordination platform—to be discussed below.

Being the teaching and transmission of the original Buddha, this “secret Dharma of the sole great matter” has its locus in the origin teaching (honmon) of the Lotus Sūtra. Up until this point, Nichiren had merely asserted the superiority of the Lotus Sūtra over all others; now he turned his attention to its latter fourteen chapters. “The teaching of three thousand realms in one thought-moment is found only in the origin teaching of the Lotus Sūtra, hidden in the depths of the text of the ‘Fathoming the Lifespan’ chapter,” he wrote. Where Chih-i had derived the doctrine of three thousand realms in one thought-moment from the trace teaching, specifically from the “Skillful Means” chapter, Nichiren now identified it with the origin teaching: thus the “one thought-moment containing three thousand realms” becomes the thought-moment of the original Buddha. This was not entirely a novel move but was closely related to medieval Tendai associations of kanjin or “mind-contemplation” specifically with the origin teaching. Nichiren’s emphasis on the origin teaching was distinctive, however, in that he defined it as uniquely related to the Final Dharma age. For him, the origin teaching mediated a “great secret Dharma,” embodied as the five characters of the daimoku, that had been transferred by Śākyamuni Buddha to the bodhisattvas who had emerged from beneath the earth, especially for the mappō era:

“Now at the beginning of the Final Dharma age, Hinayāna is used to attack Mahāyāna, the provisional is used to repudiate the true. East and west are confused, and heaven and earth are turned upside down. … The heavenly deities forsake the country and do not protect it. At this time, the bodhisattvas who sprang up from the earth will appear for the first time in the world to bestow upon the children the medicine of the five characters myōhō-renge-kyō.” (Page 260)