Nichiren is a disciple of the Buddha in his True Identity

"The Great Teacher T’ien-t’ai was a disciple of the Buddha in his transient status. But I, Nichiren, am a disciple of the Buddha in his true identity, and thus I am able to expound in full these matters that pertain to the essential teaching." - On the Importance of the Expedient Means and Lifespan Chapters of the Lotus Sutra