Except for the Eternal Buddha revealed in the essential section of the Lotus Sūtra, Buddhas all attained Buddhahood for the first time in this life and possess three kinds of bodies (the Dharma Body, Reward Body and Accommodative Body). Accommodative Buddhas are finite Buddhas who appear in this world, showing both beginning (attaining Buddhahood) and ending (entering nirvana). The Reward Body is obtained as the reward for completing the bodhisattva practice and having mastered the wisdom of the Buddha. Buddhas in this body (Reward Buddhas) therefore has the beginning (attaining Buddhahood) but no ending (entering nirvana). The Dharma Body is the body of fundamental truth, the Dharma to which the Buddha is enlightened, which is immaterial having no beginning or ending. The Vairocana Buddha of the Flower Garland School and the Great Sun Buddha of the True Word School are claimed to be the Buddhas in Reward Body and Dharma Body respectively.

The Buddha revealed in the essential section of the Lotus Sūtra is the One attaining Buddhahood in the eternal past. He, too, possesses the three kinds of the Buddha Body. In this Eternal Buddha, the three bodies are fused in one, having no beginning and no ending, and He lives forever from the eternal past to the infinite future to guide the people.

Ichidai Goji Keizu, Genealogical Chart of the Buddha’s Lifetime Teachings in Five Periods, Writings of Nichiren Shōnin, Doctrine 3, Page 250