This place, the valley of Minobu, is northwest of Hakii County, which is one of the three counties (Iino, Mimaki, and Hakii) owned by Lord Hakii Sanenaga of Kai Province (Yamanashi Prefecture). To the north, the mountain of Minobu stretches toward the sky. To the south, the Takatori Mountain stretches toward the clouds. To the east, Tenshi’s high mountain approaches the sun. To the west, the tall, steep mountains tower and join Mt. Shirane. The monkey’s cries echo toward the sky, while the cicadas’ chirps vibrate on the ground. In my eyes, this place looks like Mt. Sacred Eagle of India and Mt. T’ien-t’ai of China. Though I am neither Śākyamuni Buddha nor Grand Master T’ien-t’ai, I respectfully recite the Lotus Sūtra day and night, and expound the Great Concentration and Insight morning and evening. So Minobu looks to me exactly like the Pure Land of Mt. Sacred Eagle and differs little from Mt. T’ien-t’ai.

Matsuno-dono Nyōbō Gohenji, Reply to the Wife of Lord Matsuno, the Nun of Kubo, Writings of Nichiren Shōnin, Volume 7, Followers II, Page 72

[T]he “3,000 existences contained in one thought” doctrine is based on the three realms of existence: the realm of living beings, the realm of five components, and the realm of environment. Putting aside the first two realms for now, the third realm of environment includes trees and plants. The five colors of paint are made of trees and plants and therefore a portrait painted with colors of paint is made of trees and plants. Also, a wooden statue is made of wood. It is the power of the Lotus Sūtra that inspires a soul into these portraits and wooden statues. This is based on the “3,000 existences contained in one thought” doctrine perceived by Grand Master T’ien-t’ai. Applied to living beings, this doctrine means the “attainment of Buddhahood with one’s present body. ” Applied to the portraits and wooden statues, it means the “attainment of Buddhahood by trees and plants.”

Applauding the doctrine of T’ien-t’ai expounded in his Great Concentration and Insight, Grand Master Chang-an states, “The doctrine of ‘tranquility and contemplation’ has never been made as clear as this,” while Grand Master Miao-lê states in his Annotations on the Great Concentration and Insight, “Preaching that insentient beings such as trees and plants possess the Buddha-nature, T’ien-t’ai startled the people.” This doctrine of “3,000 existences contained in one thought” had never appeared before T’ien-t’ai nor was it to appear again. If it did appear later, it must have been plagiarized from his doctrine.

Shijō Kingo Shakabutsu Kuyō-ji, Opening the Eyes Service of Shijō Kingo’s Statue of Śākyamuni, Writings of Nichiren Shōnin, Volume 6, Followers I, Page 132

The ancient gods of India, China, and Japan also attended the assembly. Goddess Amaterasu, Great Bodhisattva Hachiman, and the gods of Kumano and Suzuka cannot dispute with the words that attest to the truth of the Lotus Sūtra. The Lotus Sūtra is supreme among all the scriptures of Buddhism. It is like a lion, the king of animals that run on the earth, and the eagle, the king of birds that fly in the sky.

Sennichi-ama Gozen Gohenji, A Reply to My Lady Nun Sennichi, Writings of Nichiren Shōnin, Faith and Practice, Volume 4, Page 146

Recent scholars of the Tendai Sect and many other schools hold that the Lotus Sūtra preaches only attaining enlightenment by persons of the Two Vehicles of śrāvaka and pratyekabuddha and the doctrine of the Eternal Buddha. I ask them in return:

If you concede that only the Lotus Sūtra expounds the dharma of attaining enlightenment by persons of the Two Vehicles and the concept of the Eternal Buddha, is not it the most wonderful of the Lotus Sūtra? If the dharma of attaining enlightenment by the Two Vehicles was not revealed in any sūtras, then how could the Buddha’s disciples attain Buddhahood, like the ten great disciples of the Buddha including Kāśyapa, who excelled in the dhuta (frugal living); Śāripūtra, who was the wisest of all the Buddha’s disciples; and Maudgalyāyana, who possessed supernatural powers; the other disciples, the twelve hundred arhats (saints who have freed themselves from all craving and the cycle of rebirth); the twelve thousand śrāvaka or hearers of the Buddha’s teachings and the countless people in the realms of the Two Vehicles (of śrāvaka and pratyekabuddha)? All these people, without encountering the Lotus Sūtra, would not have been able to attain Buddhahood from the eternal past, nor would they ever be able to. For a practicer of Buddhism, wouldn’t this be an enormous defect? What would happen to those who supported such disciples of Buddha as Kāśyapa—the King of the Brahma Heaven, Indra, the four kinds of devotees, the eight kinds of beings who protect Buddhism besides monks and nuns—if the people of the Two Vehicles could not attain enlightenment?

Shōjō Daijō Fumbetsu-shō, The Differences between Hinayāna and Mahāyāna Teachings, Writings of Nichiren Shōnin, Doctrine 2, Page 193-194

[A letter of explanation written by Nichiren Shōnin on behalf of Shijō Yorimoto on the 25th of the sixth month in the third year of the Kenji Period (1277) and submitted to the lord of the Ema Family.]

In order to make sure which is the right teaching for attaining Buddhahood, I have listened to the words and sermons of various priests. As a result, I have come to believe in the Lotus Sūtra, in which it is expounded that Nichiren Shōnin is the Bodhisattva Superior Practice commanded by Śākyamuni Buddha, Lord of the Sahā World and parent of all living beings, to appear in the Latter Age of Degeneration as a messenger of the Buddha with the duty of propagating the Lotus Sūtra.

Yorimoto Chinjō, Yorimoto’s Letter of Explanation, Writings of Nichiren Shōnin, Volume 5, Page 110

If the concept of the Eternal Buddha (enlightened since the infinite past) had not been expounded in the Lotus Sūtra, then all the Buddhas throughout the past, present and future would have been mere momentary Buddhas, due to the principle of impermanence. It would be as futile as having no sun or moon even though there are many stars in the sky, or as plants trying to grow in the ground without soil. This conclusion has been based on your recognition, however, of the supremacy of the Lotus Sūtra, which teaches the concept of the Eternal Buddha and enlightenment of all people of the Two Vehicles (of śrāvaka and pratyekabuddha).

Shōjō Daijō Fumbetsu-shō, The Differences between Hinayāna and Mahāyāna Teachings, Writings of Nichiren Shōnin, Doctrine 2, Page 194

Emperor Aśoka governed most of the Jambudvīpa around which the sun in the sky revolves. In the past when he was a five-year-old boy named Tokushō, he donated a rice cake made of sand. The merit of this donation caused him to be reborn in this world as a great ruler. It was not due to a special ambition of Tokushō, whose donation was a part of child’s play. Nevertheless, he was able to gain such a great reward due to the holiness of the Buddha.

This applies much more so for you who offered a donation to the Lotus Sūtra, which is far more exalted than the Buddha to whom Emperor Aśoka donated a rice cake. The difference between the two is like a star against the moon or a light against the sun. Thus your blessing is much greater than that of Emperor Aśoka.

Kubo-ama Gozen Gohenji, A Response to My Lady, the Nun of Kubo, Writings of Nichiren Shōnin, Volume 7, Followers II, Page 91-92