Nichiren Daishonin wrote this letter at Mount Minobu on the fourth day of the eighth month, 1277. Yasaburo, the believer to whom it was addressed, was a different person from the Funamori Yasaburo who sheltered the Daishonin during his exile in Izu. According to one explanation, he was a certain Saito Yasaburo who lived at Numazu in Suruga Province. The wording of the last paragraph suggests that he may have been a samurai.

In any event, the recipient of this Gosho was evidently preparing for an upcoming debate with a priest of the Pure Land sect and had sought the Daishonin's advice. This letter is the Daishonin's reply. It can be roughly divided into two parts. The first and longer part outlines the general argument that Yasaburo should present in debating with a follower of the Pure Land sect. The second, beginning from "If that priest says something in reply . . . ," instructs him in how he should press his opponent on specific points and urges him to muster a resolute spirit.

The first part of this Gosho explains that only Shakyamuni possesses the three virtues of sovereign, teacher and parent with respect to the people of this saha world. Here, the virtue of sovereign means the Buddha's power to protect all beings; the virtue of teacher indicates his wisdom to instruct and lead them to enlightenment; and the virtue of parent means his compassion to nurture them. In the Daishonin's day, due to the growing influence of the Pure Land sect, people tended increasingly to place their trust in Amida Buddha of the western paradise, hoping to win rebirth in his pure land after death. Under such circumstances, the Daishonin often stressed reverence for Shakyamuni, the historical founder of Buddhism who actually appeared in this world. Here he asserts that to worship Amida, the Buddha of another world, and slight Shakyamuni, is an act of utter disloyalty. Thus, though the believers in Amida may seem to be devoted to pious acts, they are in fact guilty of an offense far worse than that of impious men with no religious awareness whatsoever. Their grave error, the Daishonin says, is bringing disaster upon the country in the form of famine, epidemics and the impending Mongol invasion. He explains that because he knew the people were thus destined to undergo great suffering, he resolved to speak out against their misplaced faith and has suffered repeated abuse as a result.

In the concluding paragraph, the Daishonin admonishes Yasaburo not to be influenced by peripheral considerations nor to be swayed by his own mind, but to approach this critical encounter with total commitment as the decisive event of his life. With such resolve, he will be able to manifest the protection of all Buddhas and demonstrate the superiority of the Lotus Sutra, winning undying honor based on the True Law.