QUESTION: What are the differences between Mahāyāna and Hinayana teachings?

ANSWER: Generally speaking, the sūtras preached in the Agon period are Hinayana, while those preached in the Kegon, Hōdō, Hannya and Hokke-Nehan periods are Mahāyāna. In addition, those sūtras which expound the six unenlightened realms of hell, hungry spirits, beasts and birds, asura, human beings, and heavenly beings without expounding the four enlightened realms of śrāvaka, pratyekabuddha, bodhisattvas, and Buddhas are Hinayana while those which expound all the ten realms are Mahāyāna. Other than these two main distinctions, comparing the truthfulness in doctrine between the Lotus Sūtra and other sūtras, those sūtras preached in forty years or so before the Lotus Sūtra are in reality Hinayana although they are commonly called Mahāyāna sūtras; only the Lotus Sūtra is Mahāyāna.

Shugo Kokka-ron, Treatise on Protecting the Nation, Writings of Nichiren Shōnin, Doctrine 1, Page 13