[S]ince it has been revealed that Śākyamuni has attained enlightenment in the eternal past, Bodhisattvas Nikkō (Sunlight) and Gakkō (Moonlight), disciples of Medicine Master Buddha in the world to the east; Bodhisattvas Kannon (Avalokiteśvara) and Seishi (Mahāsthāmaprāpta), disciples of the Buddha of Infinite Life in a land to the west; various disciples of Buddhas in various lands throughout the universe as well as disciples of the Great Sun Buddha depicted in both the Diamond Realm Mandala and the Matrix-store Realm Mandala of the Great Sun Buddha Stūra and the Diamond Peak Sūtra now are all disciples of Śākyamuni. Since Buddhas in the worlds throughout the universe are all manifestations (funjin) of Śākyamuni Buddha, their disciples are of course Śākyamuni’s disciples. Let alone the sun, the moon, and stars, that have been in this world from its beginning, are disciples of Śākyamuni Buddha.

Kaimoku-shō, Open Your Eyes to the Lotus Teaching, Writings of Nichiren Shōnin, Doctrine 2, Page 76